Photocatalytic Activity Of Ag3PO4 Research Articles

Effect of thermal annealing on structural, morphological, optical, and photocatalytic activity of Ag3PO4 in the 17α-ethinylestradiol degradation

The improper disposal of pharmaceuticals can disrupt aquatic ecosystems in rivers and lakes, as well as impact human and animal health. Consequently, heterogeneous photocatalysis stands as a promising technology to mitigate or even eradicate these pollutants from aquatic systems. Silver phosphate crystals (Ag3PO4) exhibit exceptional photocatalytic and bactericidal properties. Ag3PO4 crystals were synthesized using the precipitation method, followed by a 6h heat treatment at temperatures of 100, 200, 300, 400, and 500 °C. X-ray diffraction data showcase structures with outstanding crystallinity, which remain stable even under fluctuating temperatures. Scanning electron microscopy images reveal shifts in material morphology as the temperature rises. Diffuse reflectance spectroscopy unveils optical band energy values ranging from 2.33 to 2.41 eV for the materials. Conversely, both Raman and infrared spectra indicate a reduction in bands linked to phosphate groups. Lastly, Ag3PO4 crystals exhibited remarkable performance in the photodegradation of 17α-ethinylestradiol (EE2) during a 280 min test, achieving removal rates of 77.5 %, 71.2 %, 92.4 %, 82.0 %, 41.3 %, and 92.5 % for crystals treated at 25, 100, 200, 300, 400, and 500 °C, respectively. Ag3PO4 crystals treated at 200 and 500 °C demonstrated the highest photocatalytic efficiency, attributed to their enhanced structural and morphological properties.

Surfactant-assisted hydrothermal synthesis and photocatalytic activity of Ag3PO4

Ag3PO4 nanoparticles were successfully synthesized using a simple and rapid hydrothermal method in the presence of cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) as surfactants; the corresponding photocatalysts were denoted as AP-CTAB and AP-SDS, respectively. The photocatalyst prepared without the surfactant was referred to as AP-0. The as-prepared materials were characterized using X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, UV–Vis diffused reflectance, BET-surface area analysis, and transmission electron microscopy. The photocatalytic activities of the AP-0, AP-CTAB, and AP-SDS catalysts were evaluated by the photodegradation of methylene blue and rhodamine B dyes under simulated visible light. The results revealed that the AP-CTAB catalyst’s photocatalytic activity was higher than that of AP-0 and AP-SDS.

High-Efficient Visible-Light Photocatalysis Performance and Light-Corrosion Resistance of Ag3PO4 Constructed by double-Z System Composites.

Novel visible-light-driven Ag3PO4/AgBr/AgI photocatalysts were prepared via a simple self-assembly strategy combined with in-situ anion-exchanging process. The photocatalytic activity of Ag3PO4 was significantly improved by constructing double-Z system. Specifically, the obtained materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectroscopy (DRS). Under visible light irradiation (λ > 420nm), the Ag3PO4/AgBr/AgI photocatalysts showed much higher photocatalytic activity than bulk Ag3PO4 for the degradation of formaldehyde (HCHO), and 100% HCHO degradation could be obtained within 28min. The degradation efficiency could be maintained in five cycles. Further electron paramagnetic resonance (ESR) tests demonstrated that both •OH and •O2- generated in the system. This study provides new insights into the fabrication of highly efficient visible-light-driven photocatalysts and facilitates their practical application in emerging environment issues.

Synthesis of adsorption‐photocatalysis bifunctional Ag3PO4/SBA‐15 for degradation of Rhodamine B

AbstractIn present work, Ag3PO4/SBA‐15 was prepared for the degradation of rhodamine B dye (RhB). The synthesized material was characterized by XRD, FTIR, FESEM, ultraviolet‐visible diffuse reflectance spectroscopy, and photoluminescence spectrometry. The obtained results indicate that Ag3PO4/SBA‐15 inherits both the adsorption ability of SBA‐15 and photocatalytic activity of Ag3PO4, therefore, exhibits high efficiency in the degradation of RhB. The kinetics of the process was also studied. The optimum reaction time was determined to be 60 minutes. The process of dye degradation is 3/2‐order with respect to rhodamine B. The material shows high ability to be recovered with the relatively high photocatalytic stability.

Boosting visible photocatalytic degradation of 2,4-dichlorophenol and phenol efficiency by stable core@shell hybrid Ag3PO4@polypyrrole

In this paper, conjugated conductive polymer polypyrrole molecules were coated on Ag3PO4 nanoparticles by chemical adsorption method. The photocatalytic activity of Ag3PO4 @polypyrrole (Ag3PO4 @PPy) was enhanced significantly with introducing PPy. Under visible light, Ag3PO4 @PPy (1.5 wt%) degraded 100 % of phenol in 12 min and 98.39 % of 2,4-dichlorophenol in 24 min, which was 2.01 times and 1.89 times higher than pure Ag3PO4, respectively. In addition, the degradation activity of core-shell structure catalyst Ag3PO4 @PPy remains 91.26 % after five cycles. The increased stability and activity of as-prepared core-shell Ag3PO4 @PPy was mainly attributed to the synergistic effect of Ag3PO4 and PPy. The high-stability PPy shell inhibits the dissolution of Ag3PO4 nanoparticles. The core-shell structure increases the contact area and a chemical bond was formed on the interface. In addition, the matched energy level structure and the outstanding charge transfer ability of PPy conjugated large π bond accelerates the photo-generated charge separation thereby improves the photoactivity and stability of Ag3PO4.

Synthesis of mo-doped Ag3PO4 photocatalytic materials for the decomposition of RhB under visible light irradiation

The Mo-doped Ag3PO4 photocatalytic material were successfully prepared with varying contents of AgNO3, NH4H2PO4 and (NH4)6Mo7O24. 4H2O with mol ratio of Ag:P:Mo in material and equals to 1: 3-x%: x%, (x = 3, 5, 8). The obtained materials were characterized by X-Ray diffraction (XRD), infrared spectra (IR), scanning electron microscopy (SEM), energy-dispersive X-ray (EDS), Raman spectroscopy. The photocatalytic activity of Ag3PO4 (APO), xMoAPO (x = 3, 5, 8) materials samples was assessed by degradation of Rhodamine B (RhB) in aqueous solution under visible light. The effect of photocatalyst xMoAPO was affected by the mole ratio of Ag:P:Mo in which xMoAPO samples with 5MoAPO sample exhibits the highest photocatalytic performance under visible light irradiation.

Fabrication of binary Ag3PO4 photocatalysts for enhanced photocatalytic degradation: Effect of PEDOT hole conductor and hybridized 1 T-containing MoS2 electron conductor

Photocatalytic activity of Ag3PO4 has been improved through the addition of poly(3,4-ethylenedioxythiophene) (PEDOT) hole conductor or 1 T-containing MoS2 electron conductor. The binary Ag3PO4 composites were synthesized using a facile ion-exchange and chemisorption method. The photocatalytic performance of the composites was evaluated through the photodegradation of methylene blue (MB) and tetracycline (TC) under solar light irradiation. the addition of PEDOT or 1 T-containing MoS2 significantly improves the visible light absorption and effectively enhances the charge separation of photogenerated electrons/holes. Photocatalytic mechanisms are proposed for both the PEDOT/Ag3PO4 and MoS2/Ag3PO4 composites. We demonstrate that the PEDOT/Ag3PO4 composite exhibits a Z-scheme mechanism where the conversion of oxygen (O2) to superoxide radical (∙O2–) occurs at the PEDOT and the formation of hydroxyl radical (∙OH) occurs at the Ag3PO4. For the MoS2/Ag3PO4 composite, the 1 T-containing MoS2 acts as a co-catalyst to accept the photogenerated electrons from the Ag3PO4. Also, due to its metallic property, the1T-containing MoS2 reduces charge transfer resistance. As a result, the MoS2/Ag3PO4 exhibits superior MB and TC photodegradation performances, giving efficiencies of 99% and 93%, respectively, under solar light irradiation.

Fabricating highly efficient Ag3PO4-Fe3O4-GO ternary nanocomposite photocatalyst: Effect of Fe3O4-GO preparation methods on photocatalytic activity

Removal of organic contaminants from aqueous environment by photo-degradation is a highly attractive and energy effective technology. Herein, we have fabricated ternary nanocomposites of Ag3PO4 by integrating into conducting GO matrix along with magnetic Fe3O4 nanoparticles and demonstrated highly efficient photocatalytic activity and easy separation. Fe3O4-GO hybrid materials fabrication methods strongly influenced on the photocatalytic activity of Ag3PO4. Integrating Ag3PO4 nanoparticles into Fe3O4-GO (Ag3O4-Fe3O4-GO-C) by co-precipitation approach exhibited stronger photocatalytic activity against Rhodamine B compared to hydrothermally prepared Fe3O4-GO (Ag3O4-Fe3O4-GO-H). Rhodamine B was degraded completely (100 %) in 15 min using Ag3O4-Fe3O4-GO-C whereas more than 45 min was required for Ag3O4-Fe3O4-GO-H. PXRD studies confirmed the formation of crystalline Fe3O4 and Ag3PO4 in both the samples. HR-TEM analysis confirmed the integration of Fe3O4 and Ag3PO4 in the GO sheets. XPS studies indicated the presence of all elements in Ag3O4-Fe3O4-GO-H and Ag3O4-Fe3O4-GO-C. Integration of magnetic Fe3O4 allowed easy separation and reusing of catalysts.

Antibacterial and antifouling properties of Ag3PO4/GO nanocomposite blended polyethersulfone membrane applied in dye separation

In this paper, the effect of Ag3PO4/GO nanocomposite upon the antibiofouling and permeation properties of polyethersulfone (PES) mixed matrix membranes were explored. Through the nonsolvent induced phase inversion process, the PES nanofiltration (NF) membrane, including Ag3PO4/GO nanomaterials was prepared. A reduction reaction used to the functionalization of Ag3PO4 on GO nanosheets. Energy-dispersive X-ray (EDX), atomic force microscopy (AFM), water contact angle (WCA), scanning electron microscopy (SEM), zeta potential, and ATR-FTIR analysis were applied for the membrane characterization. All the membranes embedded through the nanocomposites presented a better performance in comparison with the neat PES membrane. The PES membrane containing 0.5 wt% of Ag3PO4/GO exhibited (83 %) flux recovery ratio besides (13 %) irreversible resistance during filtration of BSA protein. Membrane antibacterial properties were studied through the colony-counting process by the photocatalytic activity of Ag3PO4. The PES membrane prepared with 0.5 wt% Ag3PO4/GO reduced 72 % of viable Escherichia coli and 84 % of Staphylococcus aureus in the bacterial suspensions. The nanofiltration performance of the membranes in Lanasol Blue 3R dye separation was investigated. All of the nanocomposite membranes had dye rejection higher than 85 %.

Dual-functional Ag3PO4@palygorskite composite for efficient photodegradation of alkane by in situ forming Pickering emulsion photocatalytic system

Removal of oil from water is highly imperative, because of the worldwide oil-contaminated water caused by industrial development and oil spill accidents. As a solution to meet the demand for clean energy technology, photocatalysis has drawn great attention recently. However, a major problem encountered in photodegrading oil is the difficult availability of oil by photocatalyst. To overcome this problem, a novel concept of integrating Pickering emulsification of palygorskite (PAL) clay particles with photocatalytic activity of Ag3PO4 is proposed in this work. By a simple co-precipitation method, Ag3PO4@PAL composite was prepared and used for the simultaneous emulsification and decomposition of tetradecane. Via a simple Pickering emulsion-based photocatalytic system, Ag3PO4 could contact with tetradecane directly, which effectively overcomes the agglomeration and settlement of Ag3PO4 in aqueous phase. This in situ photocatalytic system shows a higher efficiency for photodegradation of tetradecane, comparing with traditional solution-dispersed photocatalytic system. Under visible-light irradiation, the removal efficiency of tetradecane is 4.9 times higher than Ag3PO4 alone. Direct contact of Ag3PO4 with oil pollutes and sufficiently large active surface area greatly improve the efficiency of photodegrading oil. This study provides a new and simple strategy for oil photodegradation via an in situ Pickering emulsion system.

Carbon-Dot-Based Heterojunction for Engineering Band-Edge Position and Photocatalytic Performance.

A photocatalytic reaction is always governed by energy band configuration of the catalyst, but its modulation is challenging. Here, the adjustment of band-edge positions of Ag3 PO4 through fluorescent carbon dots is reported for the first time. Both Ag3 PO4 and carbon dots which keep the similar sizes constitute a heterojunction. Such heterostructure not only promotes visible light absorption, photogenerated charge separation, and transfer, but it also transforms photocatalytic activity of Ag3 PO4 from photooxidation to photoreduction due to the huge changes of band-edge positions. In addition, the heterojunction structure of carbon dots and Ag3 PO4 exhibits unique temperature-responsive photocatalytic activities and higher photocatalytic stability than the pure Ag3 PO4 . According to the contrast experiments and related characterizations, the possible mechanism of photocatalytic reaction is proposed. Therefore, this work offers an alternative route for adjusting energy band positions or tuning photocatalytic performance as well as for preparing novel carbon-dot-based heterostructure.

Connecting structural, optical, and electronic properties and photocatalytic activity of Ag3PO4:Mo complemented by DFT calculations

The present join experimental and theoretical work provides in-depth understanding on the relationship among structural, optical, and electronic properties and photocatalytic activity of Ag3PO4:Mo microcrystals. We prepared Ag3PO4 and (Mo-doped) Ag3PO4:Mo microcrystals using the chemical precipitation method. The as-synthetized samples have been characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy, transmission electron microscopy, high angle annular dark field scanning transmission electron microscopy (HAADF-STEM), energy-dispersive X-ray spectroscopy (EDS) techniques, and photoluminescence (PL) emission. Density functional theory calculations have been performed to complement the experimental results and understand the physical phenomena taking place in the structure, electronic and optical properties involved in the Mo doping process on the Ag3PO4, and consequently the photocatalytic performances of these new materials. XRD analysis showed that at a doping level below 2% the samples did not present any secondary phases, demonstrating that the Mo cations have been actually incorporated in the Ag3PO4 structure. Moreover, HAADF-STEM and EDS mapping showed that the samples were homogeneous, especially with respect to the Mo cations, and showed no signs of segregation. The Egap value and PL measurements indicated that the doping process caused structural defects in the Ag3PO4 structure. The photocatalytic activity of both the pure and Mo-doped materials was tested for the degradation of Rhodamine B under visible light irradiation. The results demonstrated that the sample of Ag3PO4:Mo with 0.5% Mo had a faster degradation rate, approximately 92% after 5 min of irradiation, while the degradation rate of the pure sample was only 46% during the same time.

Enhanced photo-stability and photocatalytic activity of Ag3PO4 via modification with BiPO4 and polypyrrole

Ag3PO4 photocatalysts modified with BiPO4 and polypyrrole (PPy) were successfully synthesized via a combination of co-precipitation hydrothermal technique and oxidative polymerization method. Their morphologies, structures and optical and electronic properties were characterized by means of scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscope (TEM), Brunauer–Emmett–Teller (BET) surface areas, X-ray diffraction (XRD), fourier transform infrared spectra (FT-IR), X-ray photo-electron spectroscopy (XPS), UV–vis diffuse reflection spectra (UV-vis DRS), photocurrent technique and electrochemical impedance spectra (EIS). The typical triphenylmethane dye (malachite green) was chosen as a target organic contaminants to estimate the photocatalytic activities and photo-stabilities of Ag3PO4-BiPO4-PPy heterostructures under visible light irradiation. The results indicated that the existence of BiPO4 and PPy not only showed great influences on the photocatalytic activity, but also significantly enhanced photo-stability of Ag3PO4 in repeated and long-term applications. The degradation conversion of Ag3PO4-BiPO4-PPy heterostructures (ABP-3) was 1.58 times of that of pure Ag3PO4. The photo-corrosion phenomenon of Ag3PO4 was effectively avoided. The photocatalytic activity of up to 87% in the Ag3PO4-BiPO4-PPy heterostructures (ABP-3) can be remained after five repeated cycles, while only about 33% of the degradation efficiency can be reserved in pure Ag3PO4. The possible mechanism of enhanced photo-stability and photocatalytic activity of Ag3PO4-BiPO4-PPy heterostructures was also discussed in this work.

Photocatalytic activity of Ag3PO4 and some of its composites under non-filtered and UV-filtered solar-like radiation

Silver phosphate is a promising photocatalyst since its energy band gap is situated in the visible range (Eg≈2.4eV), thus this material is a potential candidate for replacing titania which is photoactive only under UV. However, Ag3PO4 suffers of photocorrosion and therefore composites should be prepared to limit this detrimental effect. In this work, pure Ag3PO4 and its composites with AgI, TiO2, and hydroxyapatite were prepared by using various methods. The photoactivity of the materials was evaluated by their ability to decolorize methylene blue and to mineralize phenol under non-filtered and UV-filtered artificial solar-like radiation. The use of UV cut-off filter enhanced the photocatalytic activity of pure silver phosphate by limiting the photocorrosion of silver(I) into Ag°. For composites with AgI and TiO2, despite their lower photoactivity compared to pure Ag3PO4, the efficiency in mineralization of phenol after repeated run is stabilized by using UV cut-off filter. On the other hand, the photocatalytic efficiency of Ag3PO4 composites containing hydroxyapatite remained low mainly due to high absorption properties of hydroxyapatite. The photoactive samples showed excellent photoinduced antimicrobial properties where Gram-negative E. coli was more susceptible to photocatalytic deactivation than Gram-positive S. aureus (MRSA).

Effect of Ag+ and PO43− ratios on the microstructure and photocatalytic activity of Ag3PO4

In this work, the catalyst silver phosphate (Ag3PO[Formula: see text] with different initial ratios of Ag[Formula: see text] and PO[Formula: see text] in aqueous solution was synthesized by a simple precipitation method from AgNO3 and NH4H2PO4 which were used as the precursor. After that, the prepared samples were characterized by different techniques such as field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), UV-visible diffuse reflectance spectroscopy (UV-DRS) and decomposition evolution of rhodamine B (RhB) solution. The results indicate that the initial ratios of Ag[Formula: see text]/PO[Formula: see text] in aqueous solution can modify the morphology and also it can significantly affect the photocatalytic performance. During photocatalytic process, the rich Ag[Formula: see text] ion Ag3PO4 can form the surface plasmon resonance (SPR) of Ag nanoparticles, which inhibit the reduction of Ag3PO4 resulting in higher photocatalytic activity and stability.

Synthesis of few-layer MoS2 nanosheet-loaded Ag3PO4 for enhanced photocatalytic activity

Novel few-layer MoS2/Ag3PO4 composites were fabricated. The results indicated that Ag3PO4 nanoparticles were directly formed on the surface of few-layer MoS2. The physical and chemical properties of the few-layer MoS2/Ag3PO4 composite photocatalysts were tested in order to investigate the effects of few-layer MoS2 on the photocatalytic activity of Ag3PO4. The photocatalytic activity of the few-layer MoS2/Ag3PO4 composites was evaluated by the photocatalytic degradation of Rhodamine B (RhB) and bisphenol A (BPA) under visible light irradiation. The photocatalytic activity of the few-layer MoS2/Ag3PO4 composites was higher than that of pure Ag3PO4. The optimal few-layer MoS2 content for the organic pollutant degradation of the heterojunction structures was determined. The synergic effect between few-layer MoS2 and Ag3PO4 was found to lead to an improved photogenerated carrier separation. The stability and the possible photocatalytic mechanism of the composites were also discussed.

Visible light responsive porous Lanthanum-doped Ag3PO4 photocatalyst with high photocatalytic water oxidation activity

This paper report a facile route of synthesizing Ag3PO4 crystal with smooth surface, and La-doped Ag3PO4 crystal with porous surface by accurately controlling the kinetic parameters during chemical precipitation process. As a result of surface modification induced by La doping, the La-doped Ag3PO4 crystal shows a higher photocatalytic activity than Ag3PO4 crystal in O2 evolution from water splitting. The improved photocatalytic activity of La-doped Ag3PO4 is attributed to the synergistic effects of porous surface structure, abundant surface defects and increased surface area. The result also shows that La doping concentration has a remarkable effect on the photocatalytic activity of Ag3PO4.

The stabilization effect of surface capping on photocatalytic activity and recyclable stability of Ag3PO4

We find the stabilization effect of surface capping on the adsorption capacity and photocatalytic activity of Ag3PO4 in the recycling. The citrate anion complex (CAC) as the surface capping is confirmed to be constituted by citrate anion and silver citrate complex. The adsorption capacity of Ag3PO4 with CAC capping exhibits little increase in the subsequent cycle, whereas the one of the bare Ag3PO4 decreases by 25.8% for methylene blue (MB). The photocatalytic activity of Ag3PO4 with CAC capping is maintained, compared to marked 10% decrease of bare Ag3PO4 for degrading MB.

A Composite Photocatalyst Ag3po4/AlPO4-5 with High Photocatalytic Activites for Rhodamine B Degradation

A facile and reproducible method for the synthesis of Ag3PO4/AlPO4-5 photocatalyst has been developed to improve the photocatalytic activity of Ag3PO4. The innovation of this method is to in situ deposit Ag3PO4 nanoparticles onto the AlPO4-5 surface forming a composite photocatalyst. The improved activity of the Ag3PO4/AlPO4-5 composite photocatalyst for the degradation of rhodamine B (RhB) under visible light irradiation is attributed to the increased surface area and the enhanced absorption of RhB.