Self-cleaning antireflected surfaces based on treated PEO/SiO2 nanocomposite films

In this study, the polyethylene oxide (PEO)/SiO₂ nanoparticles (NPs) nanocomposite films with various SiO₂ NPs concentrations were prepared using an in situ formation of NPs in the polymer matrix for self-cleaning antireflected surface applications. The effect of SiO₂ NPs in PEO/SiO₂ NPs nanocomposite films on the structural, morphological, chemical, thermal, optical, and electrical properties of PEO/SiO₂ NPs nanocomposite films was performed. According to the x-ray diffraction and the differential scanning calorimetry analysis, the crystallinity degree of the nanocomposite films decreases by increasing the SiO₂ NPs concentrations. The bandgap energy of PEO/SiO₂ NPs nanocomposite films decreases from 3.95 to 3.55 eV as the SiO₂ NPs concentration increases up to 10 wt.%. The average electrical conductivity of the PEO/SiO₂ NPs nanocomposite films increases from 5.1 × 10⁻⁷ to 2.0 × 10⁻⁶ S/cm as the SiO₂ NPs concentration increases up to 10 wt.%. The refractive index decreases to 1.64 at 550 nm for the PEO/SiO₂ NPs nanocomposite films with 10 wt.% of SiO₂ NPs, and the water contact angle decreases to around 0° after thermal treatment, which confirms that the PEO/SiO₂ NPs nanocomposite films can be used as self-cleaning antireflected surfaces.     

In situ preparation of nano ZnO/hyperbranched polyimide hybrid film and their optical properties

Novel hybrid films of fluorinated hyperbranched polyimide (HBPI) and zinc oxide (ZnO) were prepared via the in situ sol-gel polymerization technique, in which mono-ethanolamine (MEA) was used as the coupling agent between the termini of HBPI and the precursor of ZnO. The hybrid films were characterized by transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) absorption, ultraviolet-visible (UV-vis) absorption, and fluorescent excitation/emission spectroscopy. The films, which originated from the colourless fluorinated HBPI structure and homogeneously dispersed ZnO nanoparticles, exhibited good optical transparency. Furthermore, two kinds of model compounds with and without ZnO and a HBPI film blended with ZnO microparticles were prepared to clarify the fluorescence mechanism in the pristine HBPI and in situ hybrid films. Efficient energy transfer from the ZnO nanoparticles to the aromatic HBPI main chains was observed in the in situ hybrid films, whereas energy transfer occurred only from the locally excited (LE) states to the charge-transfer (CT) state in the HBPI film. These facts demonstrate that the peripheral termini of HBPI are covalently bonded to ZnO particles via the MEA function, which operates as an effective pathway for energy transfer to give intense fluorescent emission.     

Performance of EP/PpPDA and EP/PpPDA/SiO2 nanocomposite on corrosion inhibition of steel in hydrochloric acid solution

Epoxy-poly p-phenylendiamine (EP/PpPDA) and its nanocomposite with SiO₂ nanoparticles (EP/PpPDA/SiO₂) were synthesized and tested as potential corrosion inhibitors of steel in 1 M HCl solution. Performance of EP/PpPDA/SiO₂ and EP/PpPDA coatings on protection of steel against corrosion was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and Atomic force microscopy (AFM) and at various temperatures between 298 and 328 K. Changes in the coating resistance and charge-transfer resistance with temperature were analyzed to determine the activation energies of the processes involved. The determined values of activation energy showed that the EP/PpPDA/SiO₂ coating has better anti-corrosion effect than EP/PpPDA. The thermodynamic functions of dissolution processes were also calculated and discussed. The results from AFM observations indicated that the presence of SiO₂ nanoparticles increased the roughness of Epoxy-poly p-phenylendiamine/SiO₂ nanocomposite (EP/PpPDA/SiO₂). It was finally concluded that the presence of silica nanoparticles enhance the protection properties of EP/PpPDA coating as a novel potential corrosion inhibitor for steel.     

Preparation and property investigation of crosslinked alginate/silicon dioxide nanocomposite films

Crosslinked nanocomposite films of sodium alginate (SA) and silicon dioxide (SiO₂) with different SiO₂ loading values were prepared by in situ synthesis. Biocomposite films were produced by solution casting and solvent evaporation with glycerol as the plasticizer and calcium chloride as the crosslinking agent. The effects of the addition of nano silicon dioxide (nano‐SiO₂) in SA on the microstructural, physical, mechanical, and optical properties of the nanocomposite films were characterized. The results show that nano‐SiO₂ was dispersed homogeneously in the SA matrix; it thereby formed a strong interfacial interaction between the nano‐SiO₂ particles and the matrix. The transparency of the bionanocomposite films was enhanced. Thermogravimetric analysis also revealed that nano‐SiO₂ improved the thermal stability of the SA films. The incorporation of SiO₂ further reduced the water vapor permeability and swelling degree and significantly increased the tensile strength and elongation, which are parameters important for packaging industries. Finally, the lower light transmission of UV light from 200 to 250 nm indicated that SA/SiO₂ nanocomposite films could potentially be used to prevent lipid damage by UV light in food conservation. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43489.     

The utilization of poly(amide-imide)/SiO2 nanocomposite as nanofiller for strengthening of mechanical and thermal properties of poly(vinyl alcohol) nanocomposite films

The present investigation reports the preparation and characterization of the thermally stable poly(vinyl alcohol)/(poly(amide-imide)-SiO₂) nanocomposite (PVA/PAI-SiO₂ NC) films. For this reason, the surface of SiO₂ nanoparticles (NPs) was modified with N-trimellitylimido-l-methionine and subsequently, 5 wt.% of modified SiO₂ NPs were dispersed in the PAI matrix via sonochemical reaction. The resulting NC was studied by different techniques. Finally, the PAI-SiO₂ NC was employed as nanofiller and was incorporated into the PVA matrix for the enhancement of its mechanical and thermal properties. The synthesized NCs were studied by Fourier transform infrared and X-ray diffraction spectroscopy analysis. The surface topography and morphology of the NCs were studied by atomic force microscopy techniques, field emission scanning electron microscopy and transmission electron microscopy. The micrographs demonstrated that the nanofillers were homogeneously dispersed in the PVA matrix. The thermo gravimetric analysis curves indicated that the thermal decomposition of the PVA/PAI-SiO₂ NC films shifted toward higher temperature in comparison with the pure PVA. The effect of nanofiller on the mechanical properties of NC films was also explored.     

Graphene films decorated with metal sulfide nanoparticles for use as counter electrodes of dye-sensitized solar cells

The composite films of metal sulfide (MS, M = Ni, Co) nanoparticles (NPs)/graphene films were proposed to be novel transparent conductive oxide- and platinum (Pt)-free counter electrodes with high electrocatalytic activity for dye-sensitized solar cells (DSSCs). Such DSSCs show higher photovoltaic conversion efficiencies of 5.25% (NiS/graphene) and 5.04% (CoS/graphene), compared with 5.00% for (Pt/fluorine-doped tin oxide). The excellent DSSC efficiencies are mainly due to the superior electrocatalytic activity of the MS and graphene films, and highly electrical properties of graphene films (9.57 Ω/sq). The excellent charge transfer between MS NPs and graphene films is due to the unique MS NPs and high surface area graphene structure. The graphene films were directly grown on dielectric SiO₂ substrates by chemical vapor deposition. MS NPs were uniformly implanted on the graphene films by dip coating of MS precursors M(C₃H₅OS₂)₂, and further annealed at 400 °C for 30 min under Ar.     

Effects of poly (vinyl alcohol) (PVA) content on preparation of novel thiol-functionalized mesoporous PVA/SiO2 composite nanofiber membranes and their application for adsorption of heavy metal ions from aqueous solution

Thiol-functionalized mesoporous poly (vinyl alcohol)/SiO₂ composite nanofiber membranes and pure PVA nanofiber membranes were synthesized by electrospinning. The results of Fourier transform infrared (FTIR) indicated that the PVA/SiO₂ composite nanofibers were functionalized by mercapto groups via the hydrolysis polycondensation. The surface areas of the PVA/SiO₂ composite nanofiber membranes were >290 m²/g. The surface areas, pore diameters and pore volumes of PVA/SiO₂ composite nanofibers decreased as the PVA content increased. The adsorption capacities of the thiol-functionalized mesoporous PVA/SiO₂ composite nanofiber membranes were greater than the pure PVA nanofiber membranes. The largest adsorption capacity was 489.12 mg/g at 303 K. The mesoporous PVA/SiO₂ composite nanofiber membranes exhibited higher Cu²⁺ ion adsorption capacity than other reported nanofiber membranes. Furthermore, the adsorption capacity of the PVA/SiO₂ composite nanofiber membranes was maintained through six recycling processes. Consequently, these membranes can be promising materials for removing, and recovering, heavy metal ions in water.     

Preparation of transparent PVA/TiO2 nanocomposite films with enhanced visible-light photocatalytic activity

Polymer/semiconductor oxide nanocomposite films have been intensively investigated for various applications. In this work, we reported a simple hydrothermal method to fabricate highly transparent poly(vinyl alcohol)/titanium dioxide (PVA/TiO₂) nanocomposite films with enhanced visible-light photocatalytic activity. The as-prepared PVA/TiO₂ nanocomposite films showed high optical transparency in the visible region even at a high TiO₂ content (up to 40 wt.%). The determination of photocatalytic activity by photodegradation of methyl orange (MO) and colorless phenol showed that PVA/TiO₂ nanocomposite films exhibited enhanced visible-light photocatalytic activity and excellent recycle stability. This work provided new insights into fabrication of polymer/TiO₂ nanocomposites as high performance photocatalysts in waste water treatment.     

Transparent and high infrared reflection film having sandwich structure of SiO2/Al:ZnO/SiO2

New transparent and high infrared reflection films having the sandwich structure of SiO₂/Al:ZnO(AZO)/SiO₂ were deposited on the soda-lime silicate glass at room temperature by radio frequency (R.F.) magnetron sputtering. The optical and electrical properties of SiO₂ (110 nm)/AZO (860 nm)/SiO₂ (110 nm) sandwich films were compared with those of single layer AZO (860 nm) films and double layer SiO₂ (110 nm)/AZO (860 nm) films. The results show that these sandwich films exhibit high transmittance of over 85% in the visible light range (380–760 nm), and low reflection rate of below 4.5% in the wavelength range of 350–525 nm, which is not shown in the conventional single layer AZO (860 nm) films and double layer SiO₂ (110 nm)/AZO (860 nm) films. Further these sandwich films display a low sheet resistance of 20 Ω/sq by sheet resistance formula and high infrared reflection rate of above 80% in the wavelength range of 15–25 μm. In addition, the infrared reflection property of these sandwich films is determined mainly by the AZO film. The outer SiO₂ film can diminish the interference coloring and increase transparency; the inner SiO₂ film improves the adhesion of the coating to the glass substrate and prevents Ca²⁺ and Na⁺ in the glass substrate from entering the AZO film.     

Optical and structural properties of ZnO NPs and ZnO–Bi2O3 nanocomposites

Pure ZnO and ZnO–Bi₂O₃ nanocomposites with 5 wt% and 10 wt% of Bi₂O₃ content were synthesized using the co-precipitation method. Optical properties such as refractive index (n), extinction coefficient (k), bandgap (E_g), and Urbach energies, as well as the band structure, were determined by modeling the experimental transmittance and reflectance UV–Vis spectra. The deduced bandgap and Urbach energies for pure ZnO (3.758 eV) increase with the increase of the doping degree of Bi₂O₃ in ZnO–Bi₂O₃ nanocomposite films. X-ray diffraction and scanning electron microscopy (SEM) was used to study the structural and morphological properties of these nanocomposite films. Pure ZnO and nanocomposites with Bi₂O₃ exhibit crystalline domains with wurtzite hexagonal structures, and as the doping degree of Bi₂O₃ increases, the crystallite size decreases. Based on SEM micrographs, the ZnO nanoparticles (NPs) structure shows the presence of aggregation. Moreover, Bi₂O₃ NPs in the nanocomposite film led to the further aggregation in the form of large rods. The elemental and chemical properties of the nanocomposites were investigated using infrared and energy-dispersive X-ray spectroscopy. The charge transfer process in the studied system is between ZnO and Bi₂O₃ conduction bands. Density-functional theory (DFT) calculations were performed for ZnO, Bi₂O₃, and ZnO-Bi₂O₃ compounds to investigate structural, optical, and electronic properties, being in agreement with the experimental results.     

Preparation and characterization of SiO2/polydopamine/Ag nanocomposites with long-term antibacterial activity

Silver nanoparticles (Ag NPs) with diameter of approximately 10 nm were prepared by the reduction of silver nitrate using green synthesis, an eco-friendly approach. The synthesized Ag NPs were homogeneously deposited on silicon dioxide (SiO₂) particles modified with dopamine, leading to the formation of SiO₂/polydopamine (PD)/Ag nanocomposites (NCs) with a core–shell–satellite structure investigated by transmission electron microscopy. The Ag content of SiO₂/PD/Ag NCs determined by inductively coupled plasma optical emission spectrometry was approximately 5.92 wt%. The antibacterial properties of both Ag NPs and SiO₂/PD/Ag NCs against Vibrio natriegens (V. natriegens) and Erythrobacter pelagi sp. nov. (E. pelagi) were investigated by bacterial growth curves and inhibition zone. Compared to Ag NPs, the SiO₂/PD/Ag NCs exhibited superior long-term antibacterial activity, attributed to its controlled release of Ag⁺ ions.     

Nanocomposite Fe2O3–SiO2 inclusion pigments from post-functionalized mesoporous silicas

High-surface mesoporous silicas with different pore sizes were employed for the first time as silicon precursors in the synthesis of reddish Fe₂O₃–SiO₂ inclusion pigments. Interestingly, the size of included Fe₂O₃ nanoparticles was partially controlled through confinement effects into silica mesopores. Notably, impregnated samples showed a more homogeneous and efficient encapsulation of smaller and monodisperse hematite nanoparticles (sizes around 10–35 nm). Moreover, they resulted in an improved reddish color at 1000 °C within a ceramic glaze. The best red shade (a* ≈ 18) was associated to nanocomposite with smaller hematite nanoparticles (around 5 nm). These promising results suggest the possibility to improve the reddish coloration and thermostability of Fe₂O₃–SiO₂ ceramic pigments through and adequate control of confinement effects into sintered mesoporous silicas.     

Facile Fabrication of Pt-Doped Mesoporous ZnS as High Efficiency for Photocatalytic CO2 Conversion

Developing high efficiency, environmentally friendly, and low-cost mesoporous Pt/ZnS photocatalyst for CO₂ conversion to CH₃OH is significant for clean energy conversion. Herein, we described a facile synthesis of mesoporous ZnS framework decorated Pt NPs as high efficiency for CO₂ conversion through visible light illumination. The results indicated that Pt/ZnS nanocomposites showed that the structural and crystallinity integrity of polyhedral heterojunction obviously maintain after incorporating Pt NPs, and they are well-distributed on the ZnS surface with particles size about 3–5 nm. The optimized photocatalyst 1.5% Pt/ZnS nanocomposite could prominently exhibit a high photocatalytic efficiency compared to undoped ZnS. Remarkably, the yield of CH₃OH of 400 µmolg^??1 in 9 h over 1.5% Pt/ZnS nanocomposite indicated a significantly promoted CH₃OH formation, nearly 22-fold greater than that of the undoped ZnS NPs, which substantially verified the great promoting potential for conversion of clean energy. The CH₃OH formation rate over mesoporous 1.5% Pt/ZnS nanocomposite (44.5 µmolg^?1 h^?1) is larger 24 times than that of undoped ZnS NPs (1.86 µmolg^?1 h^?1). The recycled Pt/ZnS photocatalyst does not alter the CH₃OH formation remarkably after five repeating cycles with excellent durability. Electrochemical impedance spectroscopy, photocurrent response, and photoluminescence analyses were investigated to support our results and suggested mechanism for enhancement of CO₂ conversion to CH₃OH.

     

Preparation and characterization of silica/polyimide nanocomposite films based on water‐soluble poly(amic acid) ammonium salt

In this article, a series of new silica/polyimide (SiO₂/PI) nanocomposite films with high dielectric constant (>4.0), low dielectric loss (<0.0325), high breakdown strength (288.8 kV mm⁻¹), and high volume resistivity (2.498 × 10¹⁴ Ω m) were prepared by the hydrolysis of tetraethyl orthosilicate in water‐soluble poly(amic acid) ammonium salt (PAAS). The chemical structure of nanocomposite films compared with the traditional pure PI was confirmed by Fourier transform infrared spectroscopy and X‐ray diffraction patterns. The results indicated that both the PAAS and the polyamide acid (PAA) material were effectively converted into the corresponding PI material through the thermal imidization and the amorphous SiO₂ was embedded in the nanocomposite films without structural changes. Thermal stability of the nanocomposite films was increased though mechanical property was generally decreased with increasing the mass fraction of SiO₂. All the nanocomposite films exhibited an almost single‐step thermal decomposition behavior and the average decomposition temperature was about 615°C. It was concluded that the effective dispersion of SiO₂ particles in PI matrix vigorously improved the comprehensive performance of the SiO₂/PI nanocomposite films and expanded their applications in the electronic and environment‐friendly industries. POLYM. COMPOS., 38:774–781, 2017. © 2015 Society of Plastics Engineers     

Friction spot welding of PMMA with PMMA/silica and PMMA/silica-g-PMMA nanocomposites functionalized via ATRP

In the present study, the feasibility of Friction Spot Welding (FSpW) of a commercial-grade poly(methyl methacrylate) (PMMA) (PMMA GS) and PMMA 6N/functionalized silica (SiO₂) nanocomposites was investigated. The silica nanoparticles were functionalized via atom transfer radical polymerization (ATRP) with PMMA chains to achieve a uniform dispersion in the polymer matrix. The successful functionalization of silica nanoparticles with PMMA chains via ATRP was evaluated by ATR-FT-IR and TGA measurements. Rheological investigations of the silica nanocomposites showed a plateau of the storage modulus G′ at low frequencies (0.01–0.03 rad/s) as a result of elastic particle–particle interactions. Overlap friction spot welds consisting of PMMA GS and a 2 wt% SiO₂-g-PMMA nanocomposite were successfully prepared and compared to spot joints of PMMA GS welded with PMMA 6N and PMMA 6N/silica nanocomposite with 2 wt% unfunctionalized silica nanoparticles. Raman mappings of selected areas of cross-sectional plastographic specimens revealed an increased mixing behavior between the two polymer plates in the case of PMMA GS/2 wt% SiO₂-g-PMMA joints. Although the joints welded with PMMA 6N/silica nanocomposites showed a reduction of 22% in lap shear strength and 21% displacement at peak load compared with the neat PMMA spot welds, they can compete with other state-of-the-art PMMA welding techniques such as thermal bonding and ultrasonic welding, which indicates the potential of friction spot welding as an alternative fabrication technology for joining future nanocomposite engineering parts.     

Development of optically transparent ZnS/poly(vinylpyrrolidone) nanocomposite films with high refractive indices and high Abbe numbers

A series of optically transparent ZnS‐poly(vinylpyrrolidone) (PVP) nanocomposite films with high refractive indices and high Abbe numbers have been prepared. Mercaptoethanol (ME) capped ZnS nanoparticles (NPs) were introduced into the PVP polymer matrix via simple blending with high nanophase contents. ME‐ZnS NPs of around 3 nm were prepared from zinc acetate and thiourea precursors in N,N‐dimethylformamide using ME as a capping agent. Transparent nanocomposite films with high refractive indices and high Abbe numbers can be easily prepared by a conventional film casting method. TGA results indicated that the ZnS/PVP nanocomposite films exhibit good thermal stability and the measured contents of ZnS NPs in the films agree well with the theoretical values. The refractive indices and the Abbe numbers of the ZnS/PVP nanocomposite films range from 1.5061 to 1.7523 and 55.6 to 20.4 with the content of ME‐ZnS NPs varied between 0 and 80 wt %, respectively. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

N-type silk fibroin/TiO2 nanocomposite transparent films: electrical and optical properties

This paper highlights the effect of different concentrations of titanium dioxide (TiO₂) nanoparticles on the electrical and optical properties of silk fibroin (SF). TiO₂ based SF nanocomposite films were prepared using the solvent casting method. Uniform dispersion and agglomeration of nanoparticles, in nanocomposite films, were observed by field emission SEM. The conductivity of pure SF and nanocomposite films was determined by a four-point probe and the TiO₂ nanoparticles were found to bring high conductivity to the nanocomposite films. Dielectric strength improved with the addition of nanoparticles to the SF matrix. Dielectric constant and capacitance of the pure SF and nanocomposite films were measured using an LCR meter, which showed a 10-fold enhancement on the addition of nanoparticles in SF. A very unusual property, i.e. negative resistance, was observed during LCR meter analysis for the nanocomposite films for a particular range of frequency (200–550 kHz), voltage (1 V) and current (0.5–1.5 μA). TiO₂ nanoparticles changed the semiconducting behavior of the SF films from p-type to n-type as measured by the Hall effect experiment. The optical properties of pure SF and nanocomposite films were measured using a UV–visible spectrophotometer. The increased concentration of nanoparticles in the SF has effectively enhanced the absorbing coefficient, refractive index and percentage transmittance and reduced the bandgap energy. These SF/TiO₂ nanocomposite films have shown the potential to be used as dielectric and high refractive index material for optoelectronics applications. © 2021 Society of Industrial Chemistry.     

Synthesis and film performances of SiO2/P(MMA-BA) core–shell structural latex

In this study, we have successfully synthesized silica/poly(methyl methacrylate-butyl acrylate) (SiO₂/P(MMA-BA)) core–shell nanocomposite colloids via in situ emulsion copolymerization using cationic 2,2′-azobis(2-amidinopropane)dihydrochloride (AIBA) as the initiator and the 3-Glycidoxypropyl-trimethoxysilane (GPTMS)-modified SiO₂ nanoparticles as the seeds. The SiO₂ nanoparticles embedded can reach as high as 60 wt%. The nanocomposite film presents almost the same high transparency as the pure polymer film (>90% transmittance in visible range), and displays significantly improved mechanical and UV weathering resistant properties over its pure polymer film.     

Microstructural, electrical and magnetic properties of multiferroic CoFe2O4/0.68Pb(Mg1/3Nb2/3)O3-0.32PbTiO3 nanocomposite thin films

Bilayered CoFe₂O₄/0.68Pb(Mg_1/3Nb_2/3)O₃-0.32PbTiO₃ nanocomposite films are successfully prepared on Pt/Ti/SiO₂/Si substrate via simple sol-gel process. X-ray diffraction result reveals that there exists no chemical reaction or phase diffusion between the CoFe₂O₄ and 0.68Pb(Mg_1/3Nb_2/3)O₃-0.32PbTiO₃ phases. The microstructure is characterized by scanning/transmission electron microscopy (STEM). The composite thin films exhibit both strong ferroelectric and ferromagnetic responses at room temperature. The maximal magnetoelectric coupling coefficient of the nanocomposite films reaches up to 25 mV/cm Oe, occurs at a lower bias magnetic field (H_dc) of 550 Oe.     

Mesoporous BiVO4/2D-g-C3N4 heterostructures for superior visible light-driven photocatalytic reduction of Hg(II) ions

In this contribution, a Z-scheme mesoporous BiVO₄/g-C₃N₄ nanocomposite heterojunction with a considerable surface area and high crystallinity was synthesized by a simple soft and hard template-assisted approach. This material demonstrates superior visible light-driven photocatalysis for the photoreduction of Hg(II) ions. TEM and XRD results show that the mesoporous BiVO₄ NPs, with a monoclinic phase and an ellipsoid-like shape, are highly dispersed onto the porous 2D surfaces of g-C₃N₄ nanosheets with a particle size of 5–10 nm. The obtained BiVO₄/g-C₃N₄ nanocomposites with a p-n heterojunction show significantly enhanced Hg(II) photoreduction efficiency compared to the mesoporous BiVO₄ NPs and pristine g-C₃N₄. Among all synthesized photocatalysts, the 1.2% BiVO₄/g-C₃N₄ nanocomposite indicated the highest photoreduction of Hg(II) performance, reaching ~ 100% within 60 min; this result is 3.9 and 4.5 –fold larger than that of the BiVO₄ NPs and pristine g-C₃N₄. The Hg(II) photoreduction rates highly increase to 208.90, 314.95, 411.23 and 418.68 μmol g⁻¹min⁻¹ for the mesoporous 0.4, 0.8, 1.2 and 1.6% BiVO₄/g-C₃N₄ nanocomposites, respectively. The reduction rate of the mesoporous 1.2% BiVO₄/g-C₃N₄ nanocomposite demonstrated a 5.2 and 3.8 times larger increase than that of the pristine g-C₃N₄ nanosheets and pure BiVO₄ NPs. The superior Hg(II) photoreduction efficiency was ascribed to decreased carrier recombination and the improved utilization of visible light by constructing BiVO₄/g-C₃N₄ nanocomposites with a p-n junction. Transient photocurrent measurement and photoluminescence spectra were employed to confirm the possible Hg(II) photoreduction mechanism over these BiVO₄/g-C₃N₄ photocatalysts. This research provides an accessible route for the nanoengineered design of mesoporous BiVO₄/g-C₃N₄ heterostructures that demonstrated unique photocatalytic performance.