Synthesis of MoS2/g-C3N4 as a solar light-responsive photocatalyst for organic degradation

A novel molybdenum disulfide (MoS₂) and graphitic carbon nitride (g-C₃N₄) composite photocatalyst was synthesized using a low temperature hydrothermal method. MoS₂ nanoparticles formed on g-C₃N₄ nanosheets greatly enhanced the photocatalytic activity of g-C₃N₄. The photocatalyst was tested for the degradation of methyl orange (MO) under simulated solar light. Composite 3.0 wt.% MoS₂/g-C₃N₄ showed the highest photocatalytic activity for MO decomposition. MoS₂ nanoparticles can increase the interfacial charge transfer and thus prevent the recombination of photo-generated electron–hole pairs. The novel MoS₂/g-C₃N₄ composite is therefore shown as a promising catalyst for photocatalytic degradation of organic pollutants using solar energy.     

One-Step Synthesis of g-C3N4 Nanosheets with Enhanced Photocatalytic Performance for Organic Pollutants Degradation Under Visible Light Irradiation

Graphitic carbon nitride (g-C₃N₄) has received much interest as a visible-light-driven photocatalyst for degrading pollutants such as organic dyes and antibiotics. However, g-C₃N₄ bulk activity could not meet expectations due to its rapid recombination of photogenerated electron–hole pairs and low specific surface area. In our study, melamine was thermally treated one-step in the presence of NH₄Cl to produce g-C₃N₄ nanosheets. The characterizations of surface morphology and optical properties of all g-C₃N₄ samples were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectrum (XPS), transmission electron microscopy (TEM), and UV–visible diffuse reflectance spectroscopy. Compared to bulk g-C₃N₄, g-C₃N₄ nanosheets demonstrated excellent photocatalytic activities, with approximately 98% RhB removal after 210 min of visible light irradiation. Furthermore, the effect of catalyst dosage, pH, and RhB concentration on the removal percentage dye of g-C₃N₄ nanosheets was also investigated. h⁺ and ^?O₂^? species were demonstrated as the key reactive species for the RhB. Besides, ECN exposed a tetracycline degradation efficiency of 80.5% under visible-light irradiation for 210 min, which is higher than BCN (60.8%). The improved photocatalytic activity of g-C₃N₄ nanosheets is due to the restriction of the recombination of photogenerated electrons/hole pairs, as provided by photoluminescence spectra and Nyquist plot. As a result, our research may offer an effective approach to fabricating g-C₃N₄ nanosheets with high photocatalytic activity and high stability for environmental decontamination.

     

Facile one-step synthesis of pellet-press-assisted saddle-curl-edge-like g-C3N4 nanosheets for improved visible-light photocatalytic activity

Graphitic carbon nitride (g-C₃N₄) has attracted increasing interest as a visible-light-active photocatalyst. In this study, saddle-curl-edge-like g-C₃N₄ nanosheets were prepared using a pellet presser (referred to as g-CN P nanosheets). Urea was used as the precursor for the preparation of g-C₃N₄. Thermal polymerization of urea in a pellet form significantly affected the properties of g-C₃N₄. Systematic investigations were performed, and the results for the modified g-C₃N₄ nanosheets are presented herein. These results were compared with those for pristine g-C₃N₄ to identify the factors that affected the fundamental properties. X-ray diffraction analysis and high-resolution transmission electron microscopy revealed a crystallinity improvement in the g-CN P nanosheets. Fourier-transform infrared spectroscopy provided clear information regarding the fundamental modes of g-C₃N₄, and X-ray photoelectron spectroscopy (XPS) peak-fitting investigations revealed the variations of C and N in detail. The light-harvesting property and separation efficiency of the photogenerated charge carriers were examined via optical absorption and photoluminescence studies. The valence band edge and conduction band edge potentials were calculated using XPS, and the results indicated a significant reduction in the bandgap for the g-CN P nanosheets. The Brunauer–Emmett–Teller surface area increased for the g-CN P nanosheets. The photocatalytic degradation performance of the g-CN P nanosheets was tested by applying a potential and using the classical dye Rhodamine B (RhB). The RhB dye solution was almost completely degraded within 28 min. The rate constant of the g-CN P nanosheets was increased by a factor of 3.8 compared with the pristine g-C₃N₄ nanosheets. The high crystallinity, enhanced light absorption, reduced bandgap, and increased surface area of the saddle-curl-edge-like morphology boosted the photocatalytic performance of the g-CN P nanosheets.     

0D CoP cocatalyst/ 2D g-C3N4 nanosheets: An efficient photocatalyst for promoting photocatalytic hydrogen evolution

In this work, cobalt phosphide (CoP) nanoparticles were successfully decorated on an ultrathin g-C₃N₄ nanosheet photocatalysts by in situ chemical deposition. The built-in electric field formed by heterojunction interface of the CoP/g-C₃N₄ composite semiconductor can accelerate the transmission and separation of photogenerated charge-hole pairs and effectively improve the photocatalytic performance. TEM, HRTEM, XPS, and SPV analysis showed that CoP/g-C₃N₄ formed a stable heterogeneous interface and effectively enhanced photogenerated electron-hole separation. UV-vis DRS analysis showed that the composite had enhanced visible light absorption than pure g-C₃N₄ and was a visible light driven photocatalyst. In this process, NaH₂PO₂ and CoCl₂ are used as the source of P and Co, and typical preparation of CoP can be completed within 3 hours. Under visible light irradiation, the optimal H₂ evolution rate of 3.0 mol% CoP/g-C₃N₄ is about 15.1 μmol h⁻¹. The photocatalytic activity and stability of the CoP/g-C₃N₄ materials were evaluated by photocatalytic decomposition of water. The intrinsic relationship between the microstructure of the composite catalyst and the photocatalytic performance was analyzed to reveal the photocatalytic reaction mechanism.     

Dual Z-scheme heterojunction g-C3N4/Ag3PO4/AgBr photocatalyst with enhanced visible-light photocatalytic activity

Recently, there has been a significant interest in developing high-performance photocatalysts for removing organic pollutants from water environment. Herein, a ternary graphitic C₃N₄ (g-C₃N₄)/Ag₃PO₄/AgBr composite photocatalyst is synthesized using an in-situ precipitation-anion-exchange process and characterized by several spectroscopic and microscopic techniques. During the photocatalytic reaction, X-ray photoelectron spectroscopy clearly illustrated the formation of metallic Ag on the g-C₃N₄/Ag₃PO₄/AgBr composite surface. The ternary composite photocatalyst demonstrated an increased photoactivity under visible light (>420 nm), achieving a complete decolorization of methyl orange (MO) in 5 min. The ternary g-C₃N₄/Ag₃PO₄/AgBr hybrid was also applied to the 2-chlorophenol degradation under visible light, further confirming its excellent photocatalytic activity. In addition, quenching experiments revealed that holes (h⁺) and O₂^?– were the major attack species in the decolorization of MO. The enhanced photoactivity of g-C₃N₄/Ag₃PO₄/AgBr results from the efficient transfer/separation of photoinduced charges with the dual Z-scheme pathway and the charge recombination sites on the formed Ag particles.     

Rapid synthesis and characterization of advanced ceramic-polymeric nanocomposites for efficient photocatalytic decontamination of hazardous organic pollutant under visible light and inhibition of microbial biofilm

Ceramic-polymeric 3C–silicon carbide-graphitic carbon nitride (3C–SiC@g-C₃N₄) nanocomposites were synthesized by decorating cubic phased, ceramic 3C-Silicon carbide (3C–SiC) on the framework of the nanosheets of metal free polymeric graphitic carbon nitride (g-C₃N₄) by single step pulsed laser ablation in liquid (PLAL) method. Morphological, structural, elemental and optical characterizations of the synthesized 3C–SiC@g-C₃N₄ nanocomposites were carried out. X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Transmission electron microscope (TEM) and high-resolution transmission electron microscope (HRTEM) studies confirm the perfect anchoring of 3C–SiC on g-C₃N₄ nanosheets in 3C–SiC@g-C₃N₄ nanocomposites synthesized by PLAL method. Ultra-violet diffuse reflectance spectra (UV-DRS) of 3C–SiC@g-C₃N₄ indicated the enhancement of visible light absorption and also the narrowing down of band gap energy in 3C–SiC@g-C₃N₄ nanocomposites, as a result of the anchoring of 3C–SiC on g-C₃N₄. Also we noticed the decrease of photoluminescence (PL) emission intensities in the PL spectra of 3C–SiC@g-C₃N₄ with respect to pure g-C₃N₄, which indicates the reduced photo-induced charge recombination by the presence of 3C–SiC content on g-C₃N₄ nanosheets. In the application side, PLAL synthesized 3C–SiC@g-C₃N₄ nanocomposites exhibited enhanced visible light driven photocatalytic degradation of methylene blue dye in water, improved antibacterial activity against Pseudomonas aeruginosa (gram-negative) and Staphylococcus aureus (gram-positive) bacteria, and also served as better inhibiting agent for biofilm formation, compared to pure g-C₃N₄ nanosheets. It is quite obvious from our studies that this ceramic-polymeric nanocomposite, 3C–SiC@g-C₃N₄ has the potential application for antibacterial and anti-biofilm activities in addition to its remarkable photocatalytic performance.     

Amino group-rich porous g-C3N4 nanosheet photocatalyst: Facile oxalic acid-induced synthesis and improved H2-evolution activity

The reasonable modulation of tri-s-triazine structure units of g-C₃N₄ is an effective method to optimize its intrinsic electronic and optical properties, thus boosting its photocatalytic hydrogen-evolution activity. Herein, amino groups are successfully introduced into the tri-s-triazine structure units of g-C₃N₄ nanosheets to improve their H₂-evolution activity via a facile oxalic acid-induced supramolecular assembly strategy. In this case, the resulting amino group-rich porous g-C₃N₄ nanosheets display a loose and fluffy structure with a large specific surface area (70.41 m² g^?1) and pore volume (0.50 cm³? g^??1), and enhanced visible-light absorption (450–800 nm). Photocatalytic tests reveal that the amino group-rich porous g-C₃N₄ nanosheets (AP-CN1.0 nanosheets) exhibit a significantly elevated photocatalytic H₂-production activity (130.7 μmol h^?1, AQE = 5.58%), which is much greater than that of bulk g-C₃N₄ by a factor of 4.9 times. The enhanced hydrogen-generation performance of amino group-rich porous g-C₃N₄ nanosheets can be mainly attributed to the introduction of more amino groups, which can reinforce the visible-light absorption and work as the interfacial hydrogen-generation active centers to boost the photocatalytic hydrogen production. The present facile and effective regulation of tri-s-triazine structure units may provide an ideal route for the exploitation of novel and highly efficient g-C₃N₄ photocatalysts.     

Novel g-C3N4 nanosheets/CDs/BiOCl photocatalysts with exceptional activity under visible light

We fabricated novel ternary nanocomposites through integration of C-dots (carbon dots), BiOCl, and nanosheets of graphitic carbon nitride (g-C₃N₄ nanosheets) by a cost-effective route. The fabricated photocatalysts were subsequently characterized by XRD, EDX, TEM, HRTEM, XPS, FT-IR, UV-vis DRS, TGA, BET, and PL methods to gain their structure, purity, morphology, optical, textural, and thermal properties. In addition, the degradation intermediates were identified by gas chromatography-mass spectroscopy (GC-MS). Photocatalytic performance of the synthesized samples was studied by photodegradations of three cationic (RhB, MB, and fuchsine), one anionic (MO) dyes, one colorless (phenol) pollutant and removal of an inorganic pollutant (Cr(VI)) under visible light. It was revealed that the ternary nanocomposite with loading 20% of BiOCl illustrated superlative performances in the selected photocatalytic reactions compared with the corresponding bare and binary photocatalysts. Visible-light photocatalytic activity of the g-C₃N₄ nanosheets/CDs/BiOCl (20%) nanocomposite was 42.6, 27.8, 24.8, 20.2, and 15.9 times higher than the pure g-C₃N₄ for removal of RhB, MB, MO, fuchsine, and phenol, respectively. Likewise, the ternary photocatalyst showed enhanced activity of 15.3 times relative to the g-C₃N₄ in photoreduction of Cr(VI). Moreover, the ternary nanocomposite exhibited excellent chemical stability and recyclability after five cycles. Finally, the mechanism for improved photocatalytic performance was discussed based on the band potential positions.     

Synthesis and photocatalytic activity of g-C3N4/ZnO composite microspheres under visible light exposure

In this paper, a novel g-C₃N₄/ZnO composite microspheres (CZCM) with enhanced photocatalytic activity under visible light exposure were successfully prepared by a self-assembly method followed by calcination in the air. A hierarchical structure in which ZnO microspheres were closely covered with g-C₃N₄ nanosheets was constructed. The microstructure and photocatalytic activities of the CZCM were characterized. The photocatalytic property of CZCM was evaluated by degrading solution Methyl Orange (MO) and Tetracycline (TC). The effects of varied contents of g-C₃N₄ on the photocatalytic capability of CZCM were systematically investigated and the results show that the optimized CZ-15% sample exhibit much higher photocatalytic degradation efficiency than that of bare g-C₃N₄ or ZnO under identical conditions. The analysis of Photoluminescence (PL) and photocurrent (PC) independently conformed that the photo-induced electron-hole (e^?-h⁺) pairs in the CZCM were effectively generated and responsible for the observed photocatalysis. The enhanced adsorption of visible-light and the effective charge separation on the surface of CZCM enabled significant improvement of photocatalytic performance. According to the experimental results and relative energy band levels of the two semiconductors, a possible photocatalysis mechanism for the reaction process is proposed.     

Sol-gel synthesis of nanostructured ZnO/SrZnO2 with boosted antibacterial and photocatalytic activity

Due to extensive industrialization, toxic dyes and pathogenic microbes are contaminating water supplies at an alarming rate. This situation is alarming for humans and all other living organisms that directly or indirectly depend upon water. Photocatalysis is the best technique for eliminating harmful dyes and pathogenic microbes from drinking water since it is cost-effective and ecologically acceptable. To improve the effectiveness of the photocatalysis technique, materials researchers must develop an ideal photocatalyst with a narrow-bandgap, a broad absorption range, and efficient charge separation. Here, we adopted a facile sol-gel technique to synthesize a nanostructured ZnO/SrZnO₂ composite that acts as an efficient visible light-triggered photocatalyst. The prepared photocatalyst mineralized the azo dye (Congo red, CR) and destroyed the bacterial strain (Escherichia Coli, E-Coli) under visible-light-irradiation. The photocatalytic test findings revealed that the as-prepared ZnO/SrZnO₂ composite exhibited a higher photocatalytic efficiency of mineralizing 92.4% of the CR dye as compared to SrZnO₂ (57.9%) and ZnO (34.6%). Kinetic analysis revealed that the CR dye degradation rate over ZnO/SrZnO₂ nanocomposite was 5.6 times faster than pure ZnO while 2.5 times faster than SrZnO₂. Scavenger's experiments proposed that the peroxide free-radical play a key role, while the positively charged holes play a minor role in the mineralization of CR dye. Additionally, the ZnO/SrZnO₂ composite also shows better antibacterial action, as it kills E.coli more effectively by interfering with its essential cellular activities/functions. The photocatalytic and antibacterial properties of our manufactured ZnO/SrZnO₂ nanocomposite indicate that it has significant potential to mineralize the poisonous dyes and kill pathogenic microbes.     

Visible light-activated degradation of microcystin-LR by ultrathin g-C3N4 nanosheets-based heterojunction photocatalyst

Microcystins (MCs) is a harmful toxin generated by blue-green algae in water, which has seriously threatened the ecological safety of water and human body. It is urgent to develop new catalysts and techniques for the degradation of MCs. A feasible electrostatic self-assembly method was carried out to synthesize BiVO₄/g-C₃N₄ heterojunction photocatalyst with highly efficient photocatalytic ability, where BiVO₄ nanoplates with exposed {010} facets anchored to the g-C₃N₄ ultrathin nanosheets. The morphology and microstructure of the heterojunction photocatalysts were identified by XRD, SEM, TEM, XPS, and BET. The g-C₃N₄ nanosheets have huge surface area over 200 m²/g and abundant mesoporous ranging from 2-20 nm, which provides tremendous contact area for BiVO₄ nanoplates. Meanwhile, the introduction of BiVO₄ led to red-shift of the absorption spectrum of photocatalyst, which was characterized by UV-vis diffuse reflection spectroscopy (DRS). Compared with pure BiVO₄ and g-C₃N₄, the BiVO₄/g-C₃N₄ heterojunction shows a drastically enhanced photocatalytic activity in degradation of microcystin-LR (MC-LR) in water. The MC-LR could be removed within 15 minutes under the optimal ratio of BiVO₄/g-C₃N₄. The outstanding performance of the photocatalyst is attributed to synergetic effect of interface Z-scheme heterojunction and high active facets {010} of BiVO₄ nanoplates, which provides an efficient transfer pathway to separate photoinduced carriers meanwhile endows the photocatalysts with strong redox ability.     

Investigation of g-C3N4/ZnAl2O4 and ZnO/ZnAl2O4 nanocomposites: From synthesis to photocatalytic activity of pollutant dye model

The fabrication of nanocomposite photocatalytsts with excellent photocatalytic activity is an important step in the improved degradation of organic dyes. A series of nanocomposite photocatalysts was synthesized with g-C₃N₄ and ZnO loading contents of 10, 20 and 30%. The nanocomposites were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) surface area analysis, X-ray photoelectron spectroscopy (XPS) and diffuse reflectance spectroscopy (DRS). The optical band gaps of g-C₃N₄, ZnO and ZnAl₂O₄ were about 2.79, 3.21 and 3.55 eV, respectively. Methylene blue (MB) was degraded over the prepared photocatalysts under UV irradiation. Photocatalytic activity was about 9.1 and 9.6 times higher, respectively, on 20%g-C₃N₄/ZnAl₂O₄ and 20%ZnO/ZnAl₂O₄ nanocomposite photocatalysts than on pure ZnAl₂O₄ spinel powders. Recycling experiments showed that 20%g-C₃N₄/ZnAl₂O₄ and 20%ZnO/ZnAl₂O₄ nanocomposite photocatalysts exhibited good stability after five cycles of use.     

Developing controllable mesoporous CoTiO3/C3N4 heterostructures for enhanced photocatalytic performances

Excellent charge carrier kinetics and high light absorption capability are key factors in increasing photocatalytic efficiency. Here, novel mesoporous CoTiO₃/g-C₃N₄ heterostructures at varying CoTiO₃ percentages were synthesized utilizing an easy soft and hard template approach for the degradation of acridine orange (AO) under visible light exposure. The TEM images exhibited irregular nanocrystals containing stacked g-C₃N₄ layers with crimped nanosheets, and spherical CoTiO₃ NPs (10 nm) were uniformly distributed throughout the g-C₃N₄ layers. The results indicated that the mesoporous 3%CoTiO₃/g-C₃N₄ heterostructure exhibited the highest degradation of AO dye (100%) within 60 min compared to g-C3N4 (10%) and CoTiO3 (18%). Furthermore, the 3% CoTiO₃/g-C₃N₄ heterostructure had a better degradation rate, approximately 10.75- and 6.93-fold larger than those of g-C₃N₄ and CoTiO₃ NPs, respectively. The enhanced mesoporous CoTiO₃/g-C₃N₄ exhibited effective photoinduced carrier separation, a widened light harvesting range, and synergistic effects. Additionally, the 3% CoTiO₃/g-C₃N₄ heterostructure revealed superior photocatalytic stability in AO dye recycling degradation for long-life regeneration. A direct Z-scheme mechanism was suggested for the degradation of AO dye over mesoporous CoTiO₃/g-C₃N₄, and it was further supported by photoluminescence (PL) spectroscopy and photoelectrochemical responses. The present work demonstrates new insight and an approach to synthesizing mesoporous CoTiO₃/g-C₃N₄ heterostructures for various potential applications.     

A facile and novel construction of attapulgite/Cu2O/Cu/g-C3N4 with enhanced photocatalytic activity for antibiotic degradation

A high-performance photocatalyst, attapulgite/Cu₂O/Cu/g-C₃N₄ (ATP/Cu₂O/Cu/g-C₃N₄), was constructed via a one-pot redox strategy under anoxic calcination. The as-prepared composites were characterized by Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), N₂ adsorption-desorption isotherms (BET), photoluminescence emission (PL), and electrochemical impedance spectra (EIS). Results indicate that ultra-fine CuO nanoparticles on the surface of rod-like attapulgite are in-situ reduced by NH₃ gas to generate Cu and minority Cu₂O during the pyrocondensation of melamine. Meanwhile, the generated g-C₃N₄ membrane is uniformly encapsulated on the surface of attapulgite/Cu₂O/Cu to assemble Z-scheme Cu₂O/Cu/g-C₃N₄ heterostructure. ATP/Cu₂O/Cu/g-C₃N₄ shows improved visible light response ability and hole-electron suppression compared with ATP/g-C₃N₄. The photocatalytic performance and mechanism of the obtained photocatalyst for antibiotic degradation were evaluated by UV–Vis spectrometer and liquid chromatograph. ATP/Cu₂O/Cu/g-C₃N₄ can exhibit favorable photocatalytic activity and reusability for chloramphenicol. In addition, h⁺ and·OH radicals are the main active sites in the photocatalytic process, and Cu species play a vital role in separation and retarding recombination of electron-hole pairs.     

Attachment of ZnO nanoparticles onto layered double hydroxides microspheres for high performance photocatalysis

In this study, ZnO nanoparticles were successfully deposited on the surface of ZnMgAl–CO₃–LDHs microspheres to form ZnO/ZnMgAl–CO₃–LDHs heterojunction photocatalysts by coprecipitation process. The samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and UV–vis diffuse reflectance spectroscopy. The results show that ZnO nanoparticles with diameters about 10–80 nm are tightly grown on the nanosheets of the ZnMgAl–CO₃–LDHs microspheres. Compared with the pristine ZnMgAl–CO₃–LDHs microspheres and pure ZnO, the photocatalytic activity of the heterojunction ZnO/ZnMgAl–CO₃–LDHs photocatalyst is significantly enhanced towards the degradation of phenol under UV light irradiation. The enhancement of the photocatalytic activity of the heterojunction catalysts can be ascribed to their improved light absorption property and the lower recombination rate of the photoexcited electrons and holes during the photocatalytic reaction. The optimal molar ratio of ZnO/ZnMgAl–CO₃–LDHs for the photocatalysis is 3. The heterojunction photocatalyst ZnO/ZnMgAl–CO₃–LDHs may be a promising photocatalyst for future application in water treatment due to its excellent performance in degradation of phenol.     

Preparation of heterostructure g-C3N4/ZnO nanorods for high photocatalytic activity on different pollutants (MB,RhB, Cr(VI) and eosin)

The g-C₃N₄/ZnO nanorods were prepared by simple hydrothermal, grinding and calcination methods. The characterization of g-C₃N₄/ZnO nanorods was done by different analytical techniques such as SEM, TEM, XRD, XPS, FT-IR and UV–Vis. g-C₃N₄/ZnO nanorods with heterostructures have been successfully synthesized without changing the structure between the monomers, which broadens the visible light response range and improves several major pollutants in water degradation rate. Photocatalytic studies were done for the degradation of MB, RhB, Cr(VI) and eosin which are almost fully degraded. The experimental results show that the photocatalytic performance of the nanorods is much better than others. The g-C₃N₄/ZnO photocatalyst has excellent stability and repeated cycle performance. Basing on the results of comprehensive free radical trapping test and ESR tests, it is proposed that the main active substance of the catalyst for degrading dyes is ·0₂^-, and ·OH played significant roles in the degradation process. A good photocatalytic mechanism has been proven.     

Light-transmitting AlON carrier with enhanced photocatalytic degradation performance

A skeleton structure AlON (aluminum oxynitride) carrier with light transmission performance was prepared by carbothermal reduction and nitridation (CRN). The AlON carrier can disperse nano active components and enhance its photocatalytic performance. The microstructure of the TiO₂/AlON composite photocatalyst shows that the dispersion of the agglomerated TiO₂ is achieved by the physical adsorption mechanism, the embedding mechanism and the single particle dispersion mechanism. The morphology of the BiVO₄/AlON and g-C₃N₄/AlON composite photocatalysts further proves the universality of the AlON carrier in the dispersion of nano photocatalyst. The photocatalytic performance of the nano active component was enhanced by combining with AlON carrier. After 240 min of visible light irradiation, the degradation rate of MB increased by 7.4% (BiVO₄/AlON) and 8.1% (g-C₃N₄/AlON), respectively. High light transmittance was the main reason for AlON carrier to improve the photocatalytic performance of loaded active components. In addition, AlON carrier type composite photocatalyst can be reused for many times because it has physicochemical stability and can be recovered easily.     

Au nanoparticles-doped g-C3N4 nanocomposites for enhanced photocatalytic performance under visible light illumination

Surface and bandgap engineering of graphitic carbon nitride (g-C₃N₄) could be vital in enhancing photocatalytic performance by suppressing the recombination rate of photogenerated electron-hole pairs. The present report investigated the doping effects of various wt.% (0.2–5.0%) of gold nanoparticles (Au NPs) to g-C₃N₄ (Au/g-C₃N₄) for the enhancement of the photocatalytic efficiency of g-C₃N₄ nanocomposites. A straightforward and cost-effective synthesis methodology has been applied for the desired nanocomposites. Relevant characterization tools such as XRD, XPS, TEM, FTIR, and UV–Vis were utilized to analyze various physicochemical properties. The TEM images clearly show that spherical Au NPs were homogeneously distributed into the thin carbon nitride graphitic layers, confirming the successful doping of Au. The higher-magnification TEM image confirms that the sizes of the Au NPs varied from 15 to 25 nm. The photoactivity of the newly designed Au/g-C₃N₄ nanocomposites has been evaluated for the degradation of both methylene blue dye and the drug gemifloxacin mesylate, and their efficiencies were compared with that of bare g-C₃N₄. Our findings revealed that Au/g-C₃N₄ nanocomposites with various Au contents had superior photocatalytic activity compared to bare g-C₃N₄. However, the 1%Au/g-C₃N₄ nanocomposite could be considered the optimum photocatalyst, producing 95.13% destruction of the target dye molecule in 90 min, in contrast to the 69% achieved with bare g-C3N4, under the clean energy of visible light illumination. Additionally, the photodegradation rate of the 1%Au/g-C₃N₄ nanocomposite is 2.69 times higher than the rate of bare g-C₃N₄. This report might open a new gateway towards a straightforward and cost-effective synthesis approach for Au/g-C₃N₄ nanocomposites and provides a smooth and robust platform for the utilization of this new nanocomposite for environmental remediation processes.     

Fabrication of magnetically recoverable Fe3O4/CdS/g-C3N4 photocatalysts for effective degradation of ciprofloxacin under visible light

Photocatalytic technology is an environmentally safe method of eliminating organic pollutants and antibiotics in wastewater. In this research, the performance of Fe₃O₄/CdS/g-C₃N₄ (FCN) photocatalyst for degradation of antibiotics was studied. The composite photocatalysts with different concentrations of g-C₃N₄ were prepared. FCN has better photocatalytic activity than degradation dyes in removal of antibiotics under visible light. This indicates that FCN could effectively hinder the recombination of carriers, and the addition of g-C₃N₄ increases the optical response range of CdS. At the same time, the introduction of Fe₃O₄ magnetic nanoparticles overcomes the problem of difficulty in recovery of the powder photocatalyst. The photocatalytic activity is not reduced to any significant after three cycles of use.     

Development of g-C3N4/ZnO nanocomposite as a novel,highly effective and durable photocatalytic antibacterial coating for cotton fabric

Photocatalytic antibacterial coats are considered among the best solutions to bacterial contamination of fabrics, with the drawback of reduced efficacy after continued use and washing. In the present study, the g-C₃N₄/ZnO (CNZ) nanocomposite has been introduced as a novel cotton fabric coating, with high durability, and CNZ nanopowders were synthesized using a two-step thermal synthesis process and directly coated onto cotton fabric using the sonication technique. The synthesized nanoparticles (NPs) were examined using X-ray diffraction (XRD), UV–visible spectroscopy, photoluminescence (PL), Brunauer-Emmett-Teller (BET), and Fourier transform infrared (FTIR) analyzes. Besides, the SEM analysis confirmed the successful deposition of NPs on cotton fabric. The photodegradation of methylene blue (MB) stain was assessed as a functional test for the photocatalytic effectiveness of the coated fabric, then its antibacterial properties were evaluated under visible light, by direct contact with bacterial suspensions and culturing. The results revealed that the CNZ-coated cotton fabric containing 30% ZnO (CNZ-30) has significant photocatalytic antibacterial activity against both Escherichia coli (gram-negative), and Staphylococcus aureus (gram-positive) bacteria. The bacterial reduction rate of CNZ-30 coated fabric for both E. coli and S. aureus was above 98%, even after 18 washing cycles. This excellent performance is attributed to the effective coupling of ZnO with g-C₃N₄, improved light absorption, and reduced e⁻/h⁺ pair recombination rates. This study novel coating method can offer an environmentally friendly, cost-effective, and simple process to manufacture hybrid CNZ antibacterial cotton in the textile industry.