Enhanced visible‐light‐driven photocatalytic activities of LiInO2 by Mo6+‐doping strategy

A novel visible‐light‐driven photocatalyst of Mo‐doped LiInO₂ nanocomposite was successfully synthesized through a sol‐gel method. The effect of Mo‐doping concentrations on the microstructures and properties of LiInO₂ was characterized by X‐ray diffraction, scanning electron microscope, X‐ray photoelectron spectroscopy, photoluminescence, and ultraviolet‐visible absorption spectra. The photocatalytic properties of the as‐prepared samples were evaluated by the photocatalytic degradation of methylene blue (MB) dye under visible‐light irradiation. The results demonstrated that the photocatalytic activity of 6% Mo‐LiInO₂ reached to 98.6%, which was much higher than that of the undoped photocatalyst LiInO₂ (only 46.8%). The enhanced photocatalytic activity is ascribed to Mo‐doping strategy. The holes play an important role in the process of the photodegradation of MB. The superior photocatalytic activity of the as‐prepared Mo‐LiInO₂ nanocomposites suggests a potential application for organic dye degradation of wastewater remediation. This work provides a further understanding on tailoring the band structure of semiconductor photocatalyst for enhancing visible‐light absorption and promoting electron‐hole separation by Mo‐doping strategy.     

Visible‐Light‐Induced Degradation of Methylene Blue by SrBi3VO8 Nanoparticles

Nanosized particles of strontium bismuth vanadate SrBi₃VO₈ were prepared via the Pechini method on the base of citrate‐complexation route. The samples were characterized using X‐ray powder diffraction (XRD), scanning electron microscope (SEM), energy dispersive X‐ray spectra (EDX), X‐ray photoelectron spectroscopic (XPS), and UV–vis absorption spectrum. This bismuth‐containing vanadate presents an efficient absorption in the UV–visible light wavelength region with a narrow band‐gap energy of 2.36 eV and an indirect allowed electronic transition. It is well‐known that hybridization of the 6s and 6p orbitals of Bi³⁺ could result in lone electron pair and yield some very interesting properties. The photocatalytic activities of SrBi₃VO₈ nanoparticles were evaluated by the photodegradation of methylene blue (MB) under visible light irradiation in air atmosphere. These results indicate that SrBi₃VO₈ could be a potential photocatalyst driven by visible light. To understand the charge generation and separation process, the luminescence as well as the decay lifetimes was investigated in the same samples for photocatalysis.     

A Visible‐Light‐Driven Photocatalyst of NASICON Li2Ni2(MoO4)3 Nanoparticles

A visible‐light‐driven photocatalyst based on the well‐known cathode material of NASICON‐type Li₂Ni₂(MoO₄)₃ was prepared by a modified Pechini method. The sample was characterized by X‐ray diffraction, scanning electron microscope, transmission electron microscopy, and UV‐vis absorption spectrum. The average size of Li₂Ni₂(MoO₄)₃ particle is below 50 nm. NASICON nanoparticles Li₂Ni₂(MoO₄)₃ has an efficient absorption in the UV‐visible light wavelength region with a direct allowed electronic transition of 2.07 eV. The photocatalytic properties of Li₂Ni₂(MoO₄)₃ were evaluated by the photodegradation of methylene blue (MB). Li₂Ni₂(MoO₄)₃ has an efficient photocatalytic activity and could be a potential photocatalyst driven by visible‐light. The photocatalytic activity was discussed on the optical absorption and special hexagonal tunnel structure connected by optical active centers of MoO₄ and NiO₆ and its good conductivity.     

Highly visible light responsive metal loaded N/TiO2 nanoparticles for photocatalytic conversion of CO2 into methane

Photocatalytic reduction of carbon dioxide (CO₂) into valuable hydrocarbon such as methane (CH₄) using water as reducing agent is a good strategy for environment and energy applications. In this study, a facile and simple sol-gel method was employed for the synthesis of metal (Cu and Ag) loaded nanosized N/TiO₂ photocatalyst. The prepared photocatalysts were characterized by X-ray diffraction, transmission electron microscopy, BET Surface area analyzer, X-ray photoelectron spectroscopy and UV–vis diffuses reflectance spectroscopy. The photocatalytic conversion of CO₂ into methane was carried out under visible light irradiation (λ≥420 nm) by prepared photocatalysts in order to evaluate the photocatalytic efficiency. The results demonstrate that Ag loaded N/TiO₂ showed enhanced photocatalytic performance for methane production from CO₂ compared to other Cu–N/TiO₂, N/TiO₂ and TiO₂ photocatalysts. The improvement in the photocatalytic activity could be attributed to high specific surface area, extended visible light absorption and suppressed recombination of electron – hole pair due to synergistic effects of silver and nitrogen in the Ag–N/TiO₂ photocatalyst. This study demonstrates that Ag–N/TiO₂ is a promising photocatalytic material for photocatalytic reduction of CO₂ into hydrocarbons under visible light irradiation.     

Synthesis,physical properties,and characterization of starch‐based blend films by adding nano‐sized TiO2/poly(methyl metacrylate‐co‐acrylamide)

The purpose of this study was to improve the physical properties and to expand the application range of starch‐based blend films added nano‐sized TiO₂/poly(methyl methacrylate‐co‐acrylamide) (PMMA‐co‐AM). Starch‐based blend films were prepared by using corn starch, polyvinyl alcohol (PVA), nano‐sized PMMA‐co‐AM, nano‐sized TiO₂/PMMA‐co‐AM particles, and additives, i.e., glycerol (GL) and citric acid (CA). Nano‐sized PMMA‐co‐AM was synthesized by emulsion polymerization and TiO₂ nanoparticles were also prepared by using sol–gel method. Nano‐sized TiO₂/PMMA‐co‐AM particles were synthesized by wet milling for 48 h. The morphology and crystallinity of TiO₂, nano‐sized PMMA‐co‐AM and TiO₂/PMMA‐co‐AM particles were investigated by using the scanning electron microscope (SEM) and X‐ray diffractometer (XRD). In addition, the functional groups of the TiO₂/PMMA‐co‐AM particles were characterized by IR spectrophotometry (FTIR). The physical properties such as tensile strength (TS), elongation at break (%E), degree of swelling (DS), and solubility (S) of starch‐based films were evaluated. It was found that the adding of nano‐sized particles can greatly improve the physical properties of the prepared films. The photocatalytic degradability of starch/PVA/nano‐sized TiO₂/PMMA‐co‐AM composite films was evaluated using methylene blue (MB) and acetaldehyde (ATA) as photodegradation target under UV and visible light. The degree of decomposition (C/C₀) of MB and ATA for the films containing TiO₂ and CA was 0.506 and 0.088 under UV light irradiation and 0.586 (MB) and 0.631 (ATA) under visible light irradiation, respectively. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

On Structure,Optical Properties and Photodegradated Ability of Aurivillius‐Type Bi3TiNbO9 Nanoparticles

Bi₃TiNbO₉ nanoparticles with an acceptor dopant of Ni²⁺ ion were prepared by the conventional Pechini sol–gel synthesis. The X‐ray polycrystalline diffraction measurements (XRD) and the Rietveld refinements of Bi₃TiNbO₉ samples were completed. The surface property of Bi₃TiNbO₉ nanoparticles was investigated by transmission electron microscope, scanning electron microscope), and N₂ adsorption–desorption isotherms. Bi₃TiNbO₉ nanoparticles showed an optical band gap with energy of 3.1 eV in the UV region. While the Ni²⁺‐doping could greatly reduce the band energy of Bi₃TiNbO₉:xNi²⁺ nanoparticles to 2.79 eV (x = 0.05) and 2.61 eV (x = 0.1). This indicates that the Ni‐doped samples could be excited by UV–visible light. The photocatalytic abilities were tested by the photodegradation on methylene blue solution (MB) and phenol solutions excited by visible light. Accordingly, the photocatalytic activity was improved by the Ni‐doping in B‐sites in this Aurivillius‐type structure. The results concluded that Bi₃TiNbO₉:Ni²⁺ would be a possible candidate as a visible light‐driven photocatalyst. The effective photocatalysis was discussed on the structure characteristic and experiment such as polarized Aurivillius (Bi₂O₂)²⁺ layers, luminescence, and decay lifetimes, etc.     

Photocatalytic Performance of Nitrogen‐Doped and Cu2+ and Ag+ Co‐Doped Sodium Trititanate

Nano‐sized (i) N‐doped sodium trititanate and (ii) N and Cu²⁺ (Ag⁺) co‐doped sodium trititanates CuTi₃NO_6?x (Ag₂Ti₃NO_6?x) were prepared by a solid‐state and ion‐exchange methods, respectively. The materials were characterized by EDS, PXRD, XPS, FESEM, TEM, UV–visible DRS, and Raman spectroscopy. All the materials were crystallized in monoclinic lattice with P21/m space group. The bandgap energy of all the samples was deduced from their UV–visible DRS profiles. Visible‐light‐induced photocatalytic oxidation of the methylene blue (MB) and methyl orange (MO), cyclohexene and phenol, was examined. The Ag⁺ co‐doped trititanate exhibited the highest photocatalytic activity among the materials investigated.     

Iridium,carbon and nitrogen multiple-doped TiO2 Nanoparticles with enhanced photocatalytic activity

The aim of this research is to enhance the photocatalytic activity of TiO₂ nanoparticles for the UV–visible light by multiple-doping with Iridium, carbon and nitrogen. The tridoped TiO₂ photocatalyst were prepared by wet chemical method, and characterized by X-ray diffraction, Raman spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet-visible light diffuse reflection spectroscopy and room temperature photoluminescence spectroscopy. Besides, the photocatalytic H₂ evolution performance of Ir-C-N tridoped TiO₂ under UV–visible light irradiation was evaluated. It was found that Ir existed as Ir⁴⁺ by substituting Ti in the lattice of TiO₂; meanwhile, C and N were also incorporated into the surface of TiO₂ nanoparticles in interstitial mode. Meanwhile, Ir-C-N tridoping extended the absorption of TiO₂ into the visible light region and narrowed its band gap to ~3.0 eV, resulting in enhanced photocatalytic H₂ evolution under UV–visible light irradiation. This could be attributed to narrow band gap and proper electronic structure of TiO₂ after Ir-C-N tridoping.     

Photocatalytic degradation of dyestuff wastewater under visible light irradiation using micron‐sized mixed crystal TiO2 powders

A phase transformation of micron‐sized TiO₂ powder from anatase to rutile was attempted by heat‐treatment in order to generate a new mixed crystal TiO₂ with high associated photocatalytic activity. Heat‐treated micron‐sized TiO₂ powders at different transition stages were characterized by X‐ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FT‐IR) and transmission electron microscopy (TEM) methods. The tests of photocatalytic activity of the heat‐treated micron‐sized TiO₂ powders were conducted by the photocatalytic degradation of Rhodamine B and Acid Red B under visible light irradiation. The results indicate that mixed crystal TiO₂ photocatalyst heat‐treated at 400 °C for 60 min shows the highest photocatalytic activity. It can effectively decompose the Rhodamine B and Acid Red B in aqueous solution after 6 h visible light irradiation. A remarkable improvement in photocatalytic activity of TiO₂ is caused by the formation of combined rutile–anatase phases and separation of photogenerated electron–hole pairs. Copyright © 2007 Society of Chemical Industry     

A Visible Light Photocatalyst of Carbonate‐Like Species Doped TiO2

Carbon‐doped TiO₂ nanomaterials have been successfully synthesized via an effective two‐step procedure involving hydrothermal method and followed by a low‐temperature calcination treatment process, through which a controllable amount of carbonate‐like species could be incorporated into TiO₂. First‐principles calculations suggest the TiO₂ doped with carbon in form of carbonate‐like species can effectively extend the adsorption of the material from ultraviolet region to visible light. And it is experimentally found that carbon‐doped TiO₂ nanomaterials exhibit much higher photocatalytic activity than reference P25 and TiO_2?xN_x catalysts toward the liquid‐phase degradation of organic pollutants under visible light (420 nm < λ < 800 nm) irradiation. The presence of synergic effect between carbonate‐like doping and anatase TiO₂ is believed to play an essential role in affecting the photocatalytic reactivity, and the response to the visible light is ascribed to the narrowed band gap energy controlled by carbon doping. Moreover, the roles of active species in the photocatalytic process are compared using different types of active species scavengers. Meanwhile, the degradation mechanism of the photocatalysis is proposed. It is hoped that our work could provide valuable information on the design of carbonate‐like doped semiconductor with more excellent properties and set the foundation for the further industrial application.     

Construction of self‐organized free‐standing TiO2 nanotube arrays for effective disinfection of drinking water

BACKGROUND: In this study, the efficacy of disinfection surface water using anodic TiO₂ films was investigated. The as‐prepared photocatalyst demonstrated excellent photocatalytic disinfection of E. coli cells. Free‐standing and self‐organized TiO₂ nanotube arrays were synthesized via a facile electrochemical anodization method, prior to calcination. RESULTS: Over 95% of the initial 10⁶ cpu mL^?1 E. coli cells were inactivated within 50 min of UV‐A photocatalytic disinfection, despite the influence of various ionic species and organic compounds commonly present in groundwater. This was justified by the unique double‐walled nanotubular structure of the TiO₂ photocatalyst, which provided efficient delocalization of electron carriers and promoted anti‐recombination of photogenerated pairs of electrons and holes. Based on the experimental results obtained, cations enhanced the overall disinfection process while anions had an inhibitory effect on disinfection rates. CONCLUSION: The photocatalyst exhibited high efficiency in terms of photocatalytic disinfection of E. coli cells present in groundwater. It is deemed promising for applications in drinking water treatment owing to its superior disinfection performance, as well as high settleability, which promotes recovery and reuse of the catalyst. Copyright © 2010 Society of Chemical Industry     

Microwave photocatalysis III. Transition metal ion‐doped TiO2 thin films on mercury electrodeless discharge lamps: preparation,characterization and their effect on the photocatalytic degradation of mono‐chloroacetic acid and Rhodamine B

BACKGROUND: Mercury electrodeless discharge lamps (Hg‐EDLs) were used to generate UV radiation when exposed to a microwave field. EDLs were coated with doped TiO₂ in the form of thin films containing transition metal ions Mⁿ⁺ (M = Fe, Co, Ni, V, Cr, Mn, Zr, Ag). Photocatalytic degradation of mono‐chloroacetic acid (MCAA) to HCl, CO₂, and H₂O, and decomposition of Rhodamine B on the thin films were investigated in detail. RESULTS: Polycrystalline thin doped TiO₂ films were prepared by dip‐coating of EDL via a sol–gel method using titanium n‐butoxide, acetylacetone, and a transition metal acetylacetonate. The films were characterized by Raman spectroscopy, UV/Vis absorption spectroscopy, X‐ray photoelectron spectroscopy (XPS), electron microprobe analysis and by atomic force microscopy (AFM). The photocatalytic activity of doped TiO₂ films was monitored in the decomposition of Rhodamine B in water. Compared with the pure TiO₂ film, the UV/Vis spectra of V, Zr and Ag‐doped TiO₂ showed significant absorption in the visible region, and hence the photocatalytic degradation of MCAA had increased. The best apparent degradation rate constant (0.0125 min^?1), which was higher than that on the pure TiO₂ film by a factor of 1.7, was obtained with the Ag(3%)/TiO₂ photocatalyst. The effect of doping level of vanadium acetylacetonate on the photocatalytic efficiency of the V‐doped TiO₂ was determined. CONCLUSIONS: Transition metal ion‐doped TiO₂ thin films showed significant absorption in the visible region. The metal doped TiO₂ photocatalyst (with an appropriate amount of V, Zr and Ag) on the Hg‐EDLs increased the degradation efficiency of MCAA in a microwave field. Copyright © 2009 Society of Chemical Industry     

One-pot solvothermal synthesis of carbon dots/Ag nanoparticles/TiO2 nanocomposites with enhanced photocatalytic performance

In this paper, we reported a “green” and facile method for one-pot solvothermal synthesis of carbon dots (CDs)/Ag nanoparticles (AgNPs)/titanium dioxide (TiO₂, commercial Degussa P25) ternary nanocomposites with enhanced photocatalytic performance. The characterizations of this ternary photocatalyst were studied at length and our results revealed that the crystalline phase of TiO₂ component remained unchanged after the reaction. While the newborn AgNPs and CDs were tightly attached onto the surface of TiO₂ nanoparticles. The photocatalytic activities of photocatalysts were tested by measurements of photo-degradation on methylene blue (MB) under ultraviolet (UV) and visible light. It was showed that the photocatalytic performance of the ternary photocatalyst was superior to that of single TiO₂ or CDs/TiO₂ binary photocatalyst. It was probably attributed to the synergistic effect of the photoelectrical properties of CDs and the surface plasmon resonance (SPR) effect of AgNPs, which could both enhance the absorption of visible light and hinder the recombination of photogenerated electron-hole pairs.     

Preparation of aerochitin‐TiO2 composite for efficient photocatalytic degradation of methylene blue

An aerochitin–titania (TiO₂) composite was successfully synthesized and characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, field emission scanning electron microscopy, and N₂ adsorption isotherms. The photocatalytic activity of the composite was investigated on the degradation of the model organic pollutant, methylene blue (MB) dye, under UV irradiation. The aerochitin–TiO₂ composite showed excellent adsorptive and photocatalytic activity with a degradation degree of 98% for MB. The first‐order rate constants for the photodegradation MB by TiO₂ nanoparticles and aerochitin–TiO₂ composite were found to be (3.49 ± 0.04) × 10^?3 and (1.82 ± 0.02) × 10^?2 min^?1. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45908.     

Decomposition of gas‐phase aromatic hydrocarbons by applying an annular‐type reactor coated with sulfur‐doped photocatalyst under visible‐light irradiation

BACKGROUND: Unlike many water pollution applications, visible‐light‐driven photocatalysis of gas‐phase pollutants has been reported only rarely. The present study was performed to investigate the feasibility of applying S‐doped visible‐light‐induced TiO₂ to treat gas‐phase aromatic hydrocarbons, using a continuous air‐flow annular‐type reactor. RESULTS: The prepared S‐enhanced TiO₂ powders, along with a commercially available TiO₂ powder (Degussa P‐25), were characterized using diffuse reflectance UV‐VIS‐NIR spectrophotometry, Fourier transform infrared (FTIR) spectrophotometry, X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermogravimetry (TG) analyses. A photocatalytic activity test exhibited an increasing trend in degradation reaction rates with increase in flow rate but a decreasing trend in terms of degradation efficiencies. Several experimental conditions induced reasonably high decomposition efficiencies with respect to toluene, ethyl benzene and o,m,p‐xylenes (close to or above 90%), although benzene exhibited a somewhat lower decomposition efficiency. CONCLUSIONS: The S‐doped TiO₂ and undoped P25 TiO₂ powders exhibited different catalyst characteristics. The results demonstrate that an annular‐type reactor coated with visible‐light‐activated S‐doped TiO₂ can serve as an effective tool to treat gas‐phase aromatic hydrocarbon streams. Copyright © 2009 Society of Chemical Industry     

Preparation and characterization of a novel activated carbon‐supported N‐doped visible light response photocatalyst (TiO2−xNy/AC)

A photocatalyst, TiO_2?xN_y/AC (activated carbon (AC) supported N‐doped TiO₂), highly active in both the Vis and UV range, was prepared by calcination of the TiO₂ precursor prepared by acid‐catalyzed hydrolysis in an ammonia atmosphere. The powders were characterized by diffuse reflectance spectroscopy, scanning electron microscopy, X‐ray diffraction, N₂ adsorption, Fourier transform infrared spectroscopy and phenol degradation. The doped N in the TiO₂ crystal lattice creates an electron‐occupied intra‐band gap allowing electron‐hole pair generation under Vis irradiation (500–560 nm). The TiO_2?xN_y/AC exhibited high levels of activity and the same activity trends for phenol degradation under both Vis and UV irradiation: TiO_2?xN_y/AC calcined at 500 °C for 4 h exhibited the highest activity. The band‐gap level newly formed by doped N can act as a center for the photo‐generated holes and is beneficial for the UV activity enhancement. The performance of the prepared TiO_2?xN_y/AC photocatalyst revealed its practical potential in the field of solar photocatalytic degradation of aqueous contaminants. Copyright © 2007 Society of Chemical Industry     

Characterizations of TiO2/SiO2/Ni–Cu–Zn Ferrite Composite for Magnetic Photocatalysts

The TiO₂/SiO₂/Ni–Cu–Zn ferrite composite for magnetic photocatalysts with high photocatalytic activity is successfully prepared in this study. The composite are composed of spherical or elliptical Ni–Cu–Zn ferrite nanoparticles about 20–60 nm as magnetic cores, silica as barrier layers with thickness of 15 nm between the magnetic cores and titania shells with thickness approximately 1.5 nm. Photodegradation examination of TiO₂/SiO₂/ Ni–Cu–Zn ferrite composite was carried out in methylene blue (MB) solutions illuminated under a Xe arc lamp with 35 W and color temperature of 6000 K. The results indicated that about 47.1% of MB molecules adsorbed on the TiO₂/SiO₂/Ni–Cu–Zn ferrite composite within 30 min mixing due to it higher pore volume of 0.034 cm³/g, and after 6 h Xe lamp irradiation, 83.9% of MB 16.1% was photodegraded. Compared with the TiO₂ /Ni–Cu–Zn ferrite composite, the TiO₂/SiO₂/Ni–Cu–Zn ferrite composite with silica barrier layer prohibited the photodissolution and enhanced the photocatalytic ability. The magnetic photocatalyst shows high photocatalytic efficiency that the apparent first‐order rate constant k_obs is 0.18427 h^?1, and good magnetic property that the saturation magnetization (M_s) of is 37.45 emu/g, suggesting the magnetic photocatalyst can be easily recovered by the application of an external magnetic field.     

Bi2O3 nanoparticles incorporated porous TiO2 films as an effective p‐n junction with enhanced photocatalytic activity

Porous TiO₂ films decorated with Bi₂O₃ nanoparticles are fabricated via alkali‐hydrothermal of titanium (Ti) plate by varying the reaction time. The amorphous TiO₂ is transformed into anatase after annealing the films at 500°C in air. The p‐type Bi₂O₃ nanoparticles are successfully assembled on the surface of porous n‐type TiO₂ films through the ultrasonic‐assisted successive ionic layer adsorption and reaction (SILAR) technique to form Bi₂O₃/TiO₂ nanostructure by the two cycles. The obtained Bi₂O₃/TiO₂ films are consisted of a well‐ordered and uniform porous structure with an average pore diameter of about 100‐200 nm containing homogeneously dispersed Bi₂O₃ nanoparticles of ~5 nm diameter. Moreover, the resultant composites present excellent photocatalytic performance toward methyl blue (MB) degradation under UV and visible light irradiation, which could be mainly ascribed to the enhanced light adsorption capacity of unique composite structure and the formation of p‐n heterojunctions in the porous Bi₂O₃/TiO₂ films. This research is helpful to design and construct the highly efficient heterogeneous semiconductor photocatalysts.     

Visible light photocatalytic activity of TiO2/heat‐treated PVC film

BACKGROUND: Semiconductor TiO₂ has been investigated extensively due to its chemical stability, nontoxicity and inexpensiveness. However, the wide band gap of anatase TiO₂ (about 3.2 eV) only allows it to absorb UV light. TiO₂ nanoparticles modified by conditional conjugated polymers show excellent photocatalytic activity under visible light. However, these conjugated polymers are not only expensive, but also difficult to process. Polyvinyl chloride (PVC) was heat‐treated at high temperature to remove HCl and a C?C conjugated chain structure was obtained. When TiO₂ nanoparticles were dispersed into the conjugated polymer film derived from PVC, this composites film exhibited high visible light photocatalytic activity. RESULTS: The photocatalytic activity of TiO₂/heat‐treated PVC (HTPVC) film was investigated by degrading Rhodamine B (RhB) under visible light irradiation. The photodegradation of RhB follows apparent first‐order kinetics. The rate constants of RhB photodegradation in the presence of the TiO₂/HTPVC films with different mass content of TiO₂ are 16–56 and 4–14 times that obtained in the presence of the pure HTPVC and TiO₂/polymethyl methacrylate (PMMA) composite film, respectively. The TiO₂/HTPVC film showed excellent photocatalytic activity and stability after 10 cycles under visible light irradiation. CONCLUSION: TiO₂/HTPVC film exhibits high visible light photocatalytic activity and stability. Copyright © 2012 Society of Chemical Industry     

Selective adsorption and degradation of rhodamine B with modified titanium dioxide photocatalyst

A new highly selective photocatalyst (RhB‐MIP/TiO₂) was successfully prepared by surface molecular imprinting technique using rhodamine B (RhB) as template molecule. The adsorption kinetics show RhB‐MIP/TiO₂ possessed fast adsorption rate, and adsorption behavior followed the pseudo‐second‐order kinetics. The static binding experiments revealed RhB‐MIP/TiO₂ displayed strong affinity and high adsorption capacity for RhB. Moreover, the equilibrium adsorption rate of RhB‐MIP/TiO₂ for RhB can be well fitted by the Langmuir isotherm model. The thermodynamics parameters indicated that the binding system of RhB‐MIP/TiO₂ was endothermic and spontaneous. Compared with non‐imprinted photocatalyst (NIP/TiO₂), RhB‐MIP/TiO₂ exhibited excellent selectivity toward RhB, whose selectivity coefficient for RhB relative to rhodamine 6G (Rh6G) was 2.99. Selective photocatalytic degradation experiments indicated that the apparent rate constant for the photodegradation of RhB over RhB‐MIP/TiO₂ is 0.0212 min^?1, being 216% of that over NIP/TiO₂ (0.0098 min^?1). Therefore, RhB‐MIP/TiO₂ exhibited higher photocatalytic selectivity toward RhB. The prepared photocatalyst RhB‐MIP/TiO₂ has a promising perspective in industrial wastewater treatment. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40890.