TiO2-PES Fibrous Composite Material for Ammonia Removal Using UV-A Photocatalyst

This study focused on the development and characterization of TiO2-PES composite fibers with varying TiO2 loading amounts using a phase inversion process. The resulting composite fibers exhibited a sponge-like structure with embedded TiO2 nanoparticles within a polymer matrix. Their photocatalytic performance for ammonia removal from aqueous solutions under UV-A light exposure was thoroughly investigated. The findings revealed that PeTi8 composite fibers displayed superior adsorption capacity compared to other samples. Moreover, the study explored the impact of pH, light intensity, and catalyst dosage on the photocatalytic degradation of ammonia. Adsorption equilibrium isotherms closely followed the Langmuir model, with the results indicating a correlation between qm values of 2.49 mg/g and the porous structure of the adsorbents. The research underscored the efficacy of TiO2 composite fibers in the photocatalytic removal of aqueous under UV-A light. Notably, increasing the distance between the photocatalyst and the light source resulted in de-creased hydroxyl radical concentration, influencing photocatalytic efficiency. These findings contribute to our understanding of TiO2 composite fibers as promising photocatalysts for ammonia removal in water treatment applications.

Synthesis of AgCl/Ti_(3)C_(2)@TiO_(2)Ternary Composite Photocatalysts for Photocatalytic Oxidation of 1,4-Dihydropyridine and Tetracycline Hydrochloride

AgCl/Ti_(3)C_(2)@TiO_(2)ternary composites were prepared to form a heterojunction structure between AgCl and TiO_(2)and introduce Ti3C2 as a cocatalyst.The as-prepared AgCl/Ti_(3)C_(2)@TiO_(2)composites showed higher photocatalytic activity than pure AgCl and Ti_(3)C_(2)@TiO_(2)for photooxidation of a 1,4-dihydropyridine derivative(1,4-DHP)and tetracycline hydrochloride(TCH)under visible light irradiation(λ>400 nm).The photocatalytic activity of AgCl/Ti_(3)C_(2)@TiO_(2)composites depended on Ti_(3)C_(2)@TiO_(2)content,and the catalytic activity of the optimized samples were 6.9 times higher than that of pure AgCl for 1,4-DHP photodehydrogenation and 7.3 times higher than that of Ti_(3)C_(2)@TiO_(2)for TCH photooxidation.The increased photocatalytic activity was due to the formation of a heterojunction structure between AgCl and TiO_(2)and the introduction of Ti3C2 as a cocatalyst,which lowered the internal resistance,sped up the charge transfer,and increased the separation efficiency of photogenerated carries.Photogenerated holes and superoxide radical anions were the major active species in the photocatalytic process.

Recycling Spent LiCoO_(2)Battery as a High-efficient Lithiumdoped Graphitic Carbon Nitride/Co_(3)O_(4)Composite Photocatalyst and Its Synergistic Photocatalytic Mechanism

The ever-increasing quantity of spent lithium-ion batteries(LIBs)is both a potential environmental pollutant and a valuable resource.The spent LIBs recycling mainly aimed at the separation of valuable elements.Some issues still exist in these processes such as high energy consumption and complex separation procedures.This study avoided element separation and proposed a facile approach to transform spent LiCoO_(2) electrode into a lithium(Li)-doped graphitic carbon nitride(g-C_(3)N_(4))/Co_(3)O_(4) composite photocatalyst through one-pot in situ thermal reduction.During the thermal process,melamine served as the reductant for LiCoO_(2) decomposition and the raw material for g-C_(3)N_(4) production.Li was in situ doped in g-C_(3)N_(4) and the generated Co_(3)O_(4) was in situ integrated,forming a Li-doped g-C_(3)N_(4)/Co_(3)O_(4) composite photocatalyst.This special composite exhibited an enhanced photocatalytic performance,and its photocatalytic H2 production and RhB degradation rates were 8.7 and 6.8 times higher than those of g-C_(3)N_(4).The experiments combined with DFT calculation revealed that such enhanced photocatalytic efficiency was ascribed to the synergy effect of Li doping and Co_(3)O_(4) integrating,which extended the visible light absorption(450-900 nm)and facilitated the charge transfer and separation.This study transforms waste into a high-efficient catalyst,realizing high-valued utilization of waste and environmental protection.

Fabrication of biomaterial/TiO2 composite photocatalysts for the selective removal of trace environmental pollutants

Trace environmental pollutants have become a serious problem with special attention on the hazardous heavy metals, refractory organics, and pathogenic microorganisms. With coupling biosorption and photocatalysis to develop biomaterial/TiO2 composite photocatalysts is a promising method to remove these trace pollutants because of the synergistic effect. Biomaterials provide multiple function groups which can selectively and efficiently enrich trace pollutants onto the surface of the photocatalysts, thus facilitating the following transformation mediated by TiO2 photocatalysis. Biomaterials can also help the dispersion and recovery of TiO2, or even modify the band structure of TiO2. The fabrication of chitosan/TiO2, cellulose/TiO2, as well as other biomaterial/TiO2 composite photocatalysts is discussed in detail in this review. The application significance of these composite photocatalysts for the selective removal of trace pollutants is also addressed. Several problems should be solved before the realistic applications can be achieved as discussed in the final section.

In-situ route for the graphitized carbon/TiO composite photocatalysts with enhanced removal efficiency to emerging phenolic pollutants

TiO2 is the most photoactive material because of its superstrong photooxidizing ability,and TiO2 photocatalysis has been widely applied in sustainable water treatment and environmental remediation.However,poor sunlight or visible-light harvesting efficiency and fast recombination rate of the photogenerated charge carriers severely limit the practical applications of TiO2.To overcome these problems,the present work demonstrates a facile in-situ co-condensation method combined with hydrothermal treatment to prepare a series of graphitized carbon/TiO2 composite photocatalysts,and anatase TiO2 phase andp-p-conjugated polycyclic aromatic carbon structure are created simultaneously.As-prepared TiO2/C composites exhibit remarkably high visible-light photocatalytic activity in the degradation of aqueous emerging phenolic pollutants,acetaminophen(APAP)and methylparaben(MPB),and apparent rate constant of the TiO2/C composite with carbon doping level of 10.3%for APAP and MPB removal is 7.6 and 2.8 times higher than that of bare TiO2,and 6.2 and 2.6 times higher than that of Degussa P25 TiO2.Based on the results of photoelectrochemical experiments,indirect chemical probe measurements,and ESR spectroscopy,it is verified that doping TiO2 with graphitized carbon is responsible for this enhanced photocatalytic activity,which renders the improved visible-light harvesting ability,the accelerated separation of the photogenerated charge carriers,and enlarged BET surface areas.Through analyzing the intermediates yielded in the photodegradation process,the pathway of visible-light photocatalytic degradation of APAP and MPB over the TiO2/C composite is proposed.

Multifunctional graphene‐based composite photocatalysts oriented by multifaced roles of graphene in photocatalysis

Graphene(GR),a single‐layer carbon sheet with a hexagonal packed lattice structure,has displayed attractive potential and demonstrably become the research focus in artificial photocatalysis due to its enchanting properties in enhancing light absorption,electron transfer dynamics,and surface reactions.Currently,numerous efforts have shown that the properties of GR,which are closely correlated to the photocatalytic performance of GR‐based composites are significantly affected by the synthesis methods.Herein,we first introduce the optimization strategies of GR‐based hybrids and then elaborate the synthesis of GR‐based composite photocatalysts oriented by manifold roles of GR in photoredox catalysis,containing photoelectron mediator and acceptor,improving adsorption capacity,regulating light absorption range and intensity,as well as macromolecular photosensitizer.Beyond that,a brief outlook on the challenges in this burgeoning research field and potential evolution strategies for enhancing the photoactivity of GR‐based hybrids is presented and we anticipate that this review could provide some enlightenments for the rational construction and application of multifunctional GR‐based composite photocatalysts.

Photodecomposition of H_2S to H_2 over Cd_xZn_(1-x)S composite photocatalysts

A series of CdxZn1-xS (x = 0.1-0.9) photocatalysts were prepared by coprecipitation. They could form solid solution semiconductors with hexagonal phase in agreement with pure CdS by characterization of XRD. The photophysical properties of CdxZn1-xS photocatalysts were measured by UV-Vis diffuse reflectance spectrum and surface photovoltage spectroscopy (SPS). The band gap energy gradually reduced with the increasing of x value in CdxZn1-xS,and when x = 0.7,the Cd0.7Zn0.3S photocatalyst had the strongest sur...

Ternary Ag/AgCl/BiOIO_3 composites for enhanced visible-light-driven photocatalysis

Ternary Ag/AgC l/BiO IO3 composite photocatalysts are prepared by a facile method. Enhanced visible-light absorption and charge carrier separation are achieved after the introduction of Ag/AgC l particles into BiO IO3 systems,as revealed by ultraviolet-visible diffuse-reflectance spectrometry,photocurrent response and electrochemical impedance spectroscopy. The Ag/AgC l/BiO IO3 composites are applied to the visible-light photocatalytic oxidization of NO in air and exhibit an enhanced activity for NO removal in comparison with Ag/AgC l and pure BiO IO3. A possible photocatalytic mechanism for Ag/AgC l/BiO IO3 is proposed,which is related to the surface plasmon resonance effects of Ag metal and the effective carrier separation ability of BiO IO3. This work provides insight into the design and preparation of BiO IO3-based materials with enhanced visible-light photocatalysis ability.

Visible-Light Activities of Erbium Doped BiVO4 Photocatalysts

Er-doped BiVO4 composite photocatalyst was hydrothermal synthesized and characterized by X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray Spectroscopy, X-ray photoelectron spectroscopy, and UV-Vis diffuse reflectance spectra techniques. The activity of the catalyst was determined by oxidative decomposition of methyl orange in aqueous solution under visible-light irradiation. X-ray photoelectron spectroscopy and energy-dispersive X-ray Spectroscopy analysis revealed that the doped Er existed in the form of Er2O3. It also showed that the Er doping can enhance the visible-light absorption abilities of catalysts and their visible-light-driven photocatalytic activities in comparison with those of pure BiVO4.

TiO_2/polyaniline composites:An efficient photocatalyst for the degradation of methylene blue under natural light

Polyaniline （PAn） sensitized nanocrystalline TiO2 composites （TiO2/PAn） were successfully prepared and used as an efficient photocatalyst for the degradation of dye methylene blue （MB）. The results showed that PAn was able to sensitize TiO2 efficiently and the composite photocatalyst could be activated by absorbing both the ultraviolet and visible light （λ： 190 ～ 800 nm）, whereas pure TiO2 absorbed ultraviolet light only （λ 〈 380 nm）. Under the irradiation of natural light, MB could be degraded more efficiently on the TiO2/PAn composites than on the TiO2 Furthermore, it could be easily separated from the solution by simple sedimentation.

Photocatalytic remediation ofγ-hexachlorocyclohexane contaminated soils using TiO_2 and montmorillonite composite photocatalyst

TiO2 and montmorillonite composite photocatalysts were prepared and applied in degrading γ-hexachlorocyclohexane （γ-HCH） in soils. After being spiked with γ-HCH, soil samples loaded with the composite photocatalysts were exposed to UV-light irradiation. The results indicated that the photocatalytic activities of the composite photocatalysts varied with the content of TiO2 in the order of 10%〈70%〈50% 〈30%, Moreover, the photocatalytic activity of the composite photocatalysts with TiO2 content 30% was higher than that of the pure P25 with the same mass of TiO2. The strong adsorption capacity of the composite photocatalysts and quantum size effect may contribute to its increased photocatalytic activities. In addition, effect of dosage of composite photocatalysts and soil pH on γ-HCH photodegradation was investigated. Pentachlorocyclohexene, trichlorocyclohexene, and dichlorobenzene were detected as photodegradation intermediates, which were gradually degraded with the photodegradation evolution.

A Novel High Active TiO_2/AC Composite Photocatalyst Prepared by Acid Catalyzed Hydrothermal Method

A high active novel TiO2/AC composite photocatalyst was prepared and used for phenol degradation. It was much more active than P-25 and exhibiting good decantability, less deactivation after several runs and less sensitive to pH change. Diffuse reflectance spectra （DRS） revealed that the electronic change in TiO2 did not occur by the addition of AC. Results of SEM and XRD suggested that better TiO2 distribution can be achieved when optimal AC content was adopted. The performance of the prepared TiO2/5AC catalyst revealed great practical potential in wastewater treatment field.

Preparation of BiVO4@Fiber Composites and the Photocatalytic Property for Degradation of Organic Dyes under Visible-Light

In this article, a novel BiVO4@fibers composite photocatalyst was prepared by a process that monoclinic scheelite BiVO4 nano/micro particles were in situ formated onto fiber materials. The structure, morphology and photophysical properties of the composite materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-Vis diffuse reflectance spectroscopy, respectively. The immobilization of BiVO4 photocatalyst on fibers reduced the particle size of the photoactive phase, and a few visible-light absorption abilities. The decomposition of a non-biodegradable dye Red FN-3G was selected to examine the photocatalytic activity of the composite photocatalyst. It was found that the formation of composite materials of BiVO4 with fibers didn’t decrease the photocatalytic activity with comparison to that of pure BiVO4. Moreover, it demonstrated that when adjusting the dye solution into about pH = 3, the highest efficiency of dye degradation over the fiber composite material can be obtained.

A review on WO_(3)-based composite photocatalysts:synthesis,catalytic mechanism and diversified applications

Photocatalysis as an emerging "green" energy conversion technology has attracted domestic and international attention.This technology uses semiconductor photocatalysts to convert solar energy into directly usable chemical energy,showing great potential for application in environmental pollutant purification and clean energy production,with broad development prospects.Among many semiconductor materials,tungsten trioxide(WO_(3)) is favored by researchers in the field of photocatalysis because of its good visible light response and excellent valence band hole oxidation properties.Currently,a large number of photocatalysts based on WO_(3),in particular W03-based composite photocatalysts,have been reported,and their applications cover a wide range of fields.In order to promote the development of WO_(3)-based photocatalysts and provide a reference for colleagues,we present a systematic summary of the applications and research progress of W03-based composites in the field of photocatalysis in recent years.Starting from the structural properties of WO_(3)itself,this article summarizes the preparation methods and structure-activity relationships of WO_(3)-based composite photocatalysts.Subsequently,it introduces the current application status of existing WO_(3)-based composite photocatalysts in CO_(2) reduction,hydrogen production,nitrogen fixation,and pollutant removal.Finally,the development prospects were analyzed.

Kinetic Modeling of the Photocatalytic Reduction of Cr（VI） in the Presence of Dye Using Composite Photocatalyst

The photocatalytic properties of surface TiO2 supported zeolite in a semi batch reactor for the reduction of Cr（VI） in the presence of methyl orange dye were investigated. The prepared composite photocatalyst was characterized by SEM-EDS （scanning electron microscopy and energy dispersive spectroscopy）. The effects of operating parameters such as the pH and concentration of Cr（VI） in the absence and presence of dye were evaluated. The Cr（VI） reduction was more efficient in the ternary system （Cr（VI）/dye/TiO2-zeolite） than that of the corresponding binary system （Cr（VI）/TiO2-zeolite）. The extent of metal reduction after 210 min of irradiation was 68% at pH = 3 for the ternary system. In order to optimize the effectiveness of the composite photocatalyst on the photocatalytic reduction of Cr（VI）, kinetics and isotherm models were applied. The kinetics of Cr（VI） in the presence of dye on TiO2/zeolite composite photocatalyst followed the pseudo-first-order model while the equilibrium data correlated reasonably well with Freundlich isotherm.

Mass Production of Bi3NbO7/Bi2Zn(2/3)Nb(4/3)O7 Composites and Their Visible-light Photocatalytic Activity

Series Bi3NbO7/Bi2Zn（2/3）Nb（4/3）O7 （BN/BZN） composites were synthesized through a facile solid state reaction method. The products were characterized by X-ray diffraction（XRD）, field emission scanning electron microscopy（FE-SEM） and UV-vis diffuse reflectance spectroscopy（DRS）. When BN： BZN=0.1 mole ratio, the BN/BZN composite showed the best visible-light-driven photocatalytic performance, which decomposed nearly 100% of Rh B（10 ppm, p H=3-4） within 40 min. The results demonstrated that in-situ solid state synthesis of BN/BZN composites could be an efficient strategy to develop new photocatalyst for environmental remediation.

Preparation and photocatalysis properties of composite photocatalyst CoPcS/TiO2/K2Ti4O9

Photocatalyst CoPcS/TiO2 was prepared by sol-gel method. Composite CoPcS/TiO2/K2Ti4O9 was prepared by dipping. It was incandesced at various temperatures and modification effect was compared. The results showed that optical absorption of sample incandesce at 423K occurred significant red-shift. Light absorption width extended from ultraviolet region to visible region, especially there was an intensive absorption between 600 nm and 680 nm. X-ray diffraction spectrogram showed that TiO2 in sample still maintained anatase crystal form. Under the illumination of visible light, photocatalysis degradation experiment was taken with Eosin B as simulated pollutants. Decoloration rate of Eosin B was much improved. The rate can reach 80% in 300 minutes.

Synergistic Antibacterial Performance of a Cu/WO₃-Added PTFE Particulate Superhydrophobic Composite under Visible-Light Exposure

Addition of TiO2 to a polytetrafluoroethylene (PTFE) particle-dispersed composite contributes to the self-cleaning properties of the water-repellent composite. However, its application is limited to outdoor usage or under ultraviolet (UV) irradiation. In this study, a novel visible-light-sensitive photocatalytic and superhydrophobic material was developed by adding Cu/WO3 to a PTFE particulate composite material to overcome this deficit. A remarkable property of this novel composite material is the synergistic antibacterial performance against Escherichia coli (E. coli), Staphylo-coccus aureus, and methicillin-resistant Staphylococcus aureus compared with the addition of Cu/WO3 without PTFE particles material. During 24-h exposure in visible light at 2000 lx, the number of viable cells of the three strains on the surface of the 8wt% Cu/WO3-added PTFE particulate composite decreased from 2 – 4 × 105 colony-formation units (CFUs) to less than 10, the limit of detection. This bactericidal rate is four times higher than that of 8wt% Cu/WO3 without PTFE particles material, which is attributed to the air trapped in the rough surface of the novel material providing additional oxygen to the photocatalytic reaction. Even for exposure to visible light at 100 lx, the decrease in CFUs of E. coli on the 12wt% Cu/WO3-added PTFE particulate composite reached nearly 2.0 logs. The characterization of the Cu/WO3-added PTFE particulate composite indicated that the composite material containing 80wt% PTFE maintained a superhydrophobic or water-repellent property with a water contact angle >150。, although the Cu/WO3 in the composite material remained hydrophilic under visible light. The Cu/WO3-added PTFE particulate composite displayed photo-catalytic reactions to decompose oleic acid adsorbed on its surface and gaseous acetaldehyde under UV-A and visible-light illumination. All results demonstrate that the Cu/WO3-added PTFE particulate composite material may be used in sterilization, as a water repellent, for self-cleaning, and in the oxidative decomposition of volatile organic compounds (VOC) both indoors and outdoors.

Preparation and characterization of the TiO_2-V_2O_5 photocatalyst with visible-light activity

Visible-light responsive TiO2-V2O5 catalyst was prepared using a binary sol-gel and in-situ intercalation method. The TiO2 sol and V2O5 sol were mixed to disperse the V2O5 species in the TiO2 phase at molecular level. The binary sol was then intercalated into interspaces of polyaniline （PANI） by means of in-situ polymerization of aniline. Conglomeration of the TiO2-V2O5 dusters during the calcination process was avoided because of the wrap of polyaniline. The surface mor- phology, the crystal phases, the structure, and the absorption spectra of （PANI）,/TiO2-V2O5 and the composite catalyst were studied using SEM, XRD, FT-IR, and UV-Vis. The photoactivity of the prepared catalyst under UV and visible light irradiation were evaluated by decolorization of methylene blue （MB） solution. The results showed that the composite catalyst displayed a homogeneous anatase phase, and the vanadium pentoxide species was highly dispersed in the TiO2 phase. The composite catalyst responded to visible light because of the narrowed band gap. In this study, the catalyst with the sol volume ratio of TiO2： V2O5 = 10：1 presented the best photocatalytic activity.

Photocatalytic selective oxidation of aromatic alcohols coupled with hydrogen evolution over CdS/WO_(3) composites

Simultaneously utilizing photogenerated electrons and holes to convert renewable biomass and its derivatives into corresponding value‐added products and hydrogen(H_(2))is a promising strategy to deal with the energy and environmental crisis.Herein,we report a facile hydrothermal method to construct a direct Z‐scheme CdS/WO_(3) binary composite for photocatalytic coupling redox reaction,simultaneously producing H_(2) and selectively converting aromatic alcohols into aromatic aldehydes in one pot.Compared with bare CdS and WO_(3),the CdS/WO_(3) binary composite exhibits significantly enhanced performance for this photocatalytic coupled redox reaction,which is ascribed to the ex‐tended light harvesting range,efficient charge carrier separation rate and optimized redox capabil‐ity of CdS/WO_(3) composite.Furthermore,the feasibility of converting various aromatic alcohols to corresponding aldehydes coupled with H_(2) evolution on the CdS/WO_(3) photocatalyst is proved and a reasonable reaction mechanism is proposed.It is hoped that this work can provide a new insight into the construction of direct Z‐scheme photocatalysts to effectively utilize the photogenerated electrons and holes for photocatalytic coupled redox reaction.