Surface Of Ag3PO4 Research Articles

Design of defective silver phosphate photocatalyst using Nigella sativa seed aqueous extract for enhanced photocatalytic activity

New properties of the Ag3PO4 material have been successfully designed through surface modification of the material using natural extracts of Nigella sativa seeds. This research aims to induce changes in the band gap, defects, and atomic composition on the surface of Ag3PO4 through the coprecipitation method with Nigella sativa seed aqueous extract (NSE). The mixture of phosphate ion solution and NSE was reacted drop by drop with silver ion solution followed by aging treatment. The synthetic products were characterized using XRD, FE-SEM, FTIR, DRS, PL, Raman, and XPS. Rhodamine B dye was used as a target pollutant for photocatalytic evaluation. The results showed that NSE significantly induced changes in the band gap energy, defects, and atomic composition in the Ag3PO4 surface. The photocatalytic rate of Ag3PO4 treated with NSE increased up to 11 times higher than that of samples without NSE. This extraordinary activity is mainly due to the presence of active hole species in the valence band.

Complete photodegradation of tetracycline induced by surface microenvironment of graphitic carbon nitride/silver phosphate

Silver phosphate (Ag3PO4) is a promising photocatalyst, but the photo-corrosion issue limits an effective and comprehensive photocatalysis degradation of tetracycline (TC). In this work, a unique graphitic carbon nitride-Ag3PO4 (KCN-AP(40 %)) core-shell structure was prepared via a simple chemical sedimentation method. The unique graphitic carbon nitride sheet encloses Ag3PO4 to trap excited electrons from the conduction band position of Ag3PO4, suppressing the reduction of Ag+ and Ag metal deposition on the surface of Ag3PO4. Under visible light irradiation, the optimized KCN-AP(40 %) can photodegrade nearby 100 % of TC within 20 min with a first-order kinetic constant of 0.127 min−1, which is 3.34 and 3.97-folds higher than those of Ag3PO4 and graphitic carbon nitride, respectively. A series of factors that may affect photoactivity of KCN-AP (40 %) including pH, inorganic ions, and organic matter are investigated. In final, the photodegradation mechanisms and intermediates were proposed based on ex-situ HPLC-MS. This work explains the deep decomposition of TC and presents a facile approach for designing and manufacturing Ag3PO4 based nanohybrids.

Surface engineering of Ag3PO4 using lithium iodide for enhanced photocatalytic activity

The surface engineering of Ag3PO4 using lithium iodide was successfully carried out to induce photocatalytic properties. The Ag3PO4 surface was treated using a lithium iodide solution from low to high concentration under stirring and continued with aging. The modified Ag3PO4 samples were characterized using XRD, SEM, BET, UV–Vis DRS, PL spectra, TRPL, Raman spectra, and XPS. LiI treatment on the Ag3PO4 surface decreases a symmetric stretching [PO4] tetrahedron, P/Ag atomic ratio, and FWHM of Ag3d and P2p, and increases the kinetic energy of AgMNN Auger electrons. These phenomena were due to the incorporation of iodine on the Ag3PO4 surface and defect formation on the Ag3PO4 surface. Treatment with a low concentration of LiI solution showed higher photocatalytic activity with a rate constant of 9.05 times faster than samples without LiI treatment. The high photocatalytic activity was due to the suppression of hole and electron recombination, stronger hole species, and high adsorption on the surface of Ag3PO4.

In-depth investigation on the photostability and charge separation mechanism of Ag3PO4/g-C3N4 photocatalyst towards very low visible light intensity

A facile chemical precipitation approach was used to synthesis visible light-driven Ag3PO4/g-C3N4 photocatalysts, with varying g-C3N4 content. The photostability performances were tested against methyl orange (MO) dye removal using very low light intensity (23 W). The fabrication of g-C3N4 onto Ag3PO4 surface has resulted in a substantial enhancement in the photostability and performance of pristine Ag3PO4. The Ag3PO4/g-C3N4, with a ratio of 1:0.03, displayed a rapid and almost a complete photo-removal efficiency within 10 min under normal conditions. The improved activities under visible irradiation were attributed to the photoexcited carrier's outstanding separation efficiency as demonstrated by the band gap, photoluminescence spectra, and cyclic voltametric studies. Positive holes (h+) and superoxide radicals’ anions (O2−) were found to be the dominant species responsible for the degradation via the Z-scheme mechanism.

Synergistic redox enhancement: silver phosphate augmentation for optimizing magnesium copper phosphate in efficient energy storage devices and oxygen evolution reaction.

The implementation of battery-like electrode materials with complicated hollow structures, large surface areas, and excellent redox properties is an attractive strategy to improve the performance of hybrid supercapacitors. The efficiency of a supercapattery is determined by its energy density, rate capabilities, and electrode reliability. In this study, a magnesium copper phosphate nanocomposite (MgCuPO4) was synthesized using a hydrothermal technique, and silver phosphate (Ag3PO4) was decorated on its surface using a sonochemical technique. Morphological analyses demonstrated that Ag3PO4 was closely bound to the surface of amorphous MgCuPO4. The MgCuPO4 nanocomposite electrode showed a 1138 C g-1 capacity at 2 A g-1 with considerably improved capacity retention of 59% at 3.2 A g-1. The increased capacity retention was due to the fast movement of electrons and the presence of an excess of active sites for the diffusion of ions from the porous Ag3PO4 surface. The MgCuPO4-Ag3PO4//AC supercapattery showed 49.4 W h kg-1 energy density at 550 W kg-1 power density and outstanding capacity retention (92% after 5000 cycles). The experimental findings for the oxygen evolution reaction reveal that the initial increase in potential required for MgCuPO4-Ag3PO4 is 142 mV, indicating a clear Tafel slope of 49 mV dec-1.

The enhanced photo-stability of defective Ag3PO4 tetrahedron prepared using tripolyphosphate

Ag3PO4 is an excellent photocatalyst under visible light irradiation. However, the low stability due to photo-corrosion is still an obstacle in its application. It is a big challenge to improve stability using synthesis modification. Here, the photocatalyst stability enhancement was successfully prepared by tripolyphosphate. Photocatalyst was prepared by reacting AgNO3 solution with STPP (sodium tripolyphosphate) solution to form a white suspension. The addition of phosphate solution to the white suspension produces yellow Ag3PO4 with a new type of defective photocatalyst. The XPS measurement showed that the increase of STPP concentration significantly decreased the Ag/P atomic ratio, indicating the silver vacancy formation on the surface of Ag3PO4. The photocatalytic reaction formed a metallic Ag with a lower d-space in the cube structure occurred in the silver vacancy of Ag3PO4. This defect increases the interaction of metallic silver and Ag3PO4. The enhanced photo-stability might be induced by metallic silver that can act as a photogenerated electron acceptor.

Construction of Ag nanocluster-modified Ag3PO4 containing silver vacancies via in-situ reduction: With enhancing the photocatalytic degradation activity of sulfamethoxazole

Photocatalytic removal of sulfonamide antibiotics is an effective strategy to solve environmental pollution. Ag3PO4 is a promising anode material for photocatalytic material with photocatalytic degradation ability under ultraviolet light or natural light. Unfortunately, due to its instability, Ag+ could be reduced to Ag0 which loaded onto the surface of Ag3PO4 during the photocatalytic process, causing self-photocorrosion and resulting in the reduction of photocatalytic activity and stability. Herein, Ag3PO4 nanoparticles loaded with Ag nanoclusters containing Ag vacancies (Ag/Ag3PO4-VAg) were constructed by an in-situ reduction strategy to achieve effectively photocatalytic degradation behavior. The Ag nanoclusters loaded on the surface of Ag3PO4 can not only effectively inhibit the self-photocorrosion but also affords a localized surface plasmon resonance (LSPR) effect in the photocatalytic process, thus leading to the efficient generation and rapid transfer of photogenerated carriers behavior. In addition, the Ag vacancies in Ag3PO4 are crucial to increasing the adsorption energy of H2O for further enhancing the capture and accumulation of electrons. In detail, according to Zeta potential analysis, the strong adsorption sites of sulfamethoxazole (SMX) molecules are generated at the interface of Ag and Ag3PO4, which promote the activation of SMX molecules. A 100 ml of 20 mg/L SMX could be completely degraded within 15 min with an apparent rate constant (Kapp) of 0.306 min−1, which far exceeds the activity of most of the photocatalysts. This work may provide an attractive strategy to address the activity, stability of Ag3PO4 and and realizing the green remediation of SMX wastewater.

Construction of Bi2Sn2O7/Ag/Ag3PO4 heterojunction and its photocatalytic degradation properties

BackgroundThe construction of heterojunction photocatalysts with excellent redox ability is considered as an effective strategy to address refractory pollutants. MethodsThe novel Bi2Sn2O7/Ag/Ag3PO4 Z-scheme heterojunctions were designed and constructed by a hydrothermal combined precipitation method. The Ag3PO4 microspheres were simply precipitated and supported the nanoparticles Bi2Sn2O7, and then Ag+ cations on the surface were photoreduced to Ag0 nanoparticles anchored on the surface of Ag3PO4. Significant findingsUnder visible light irradiation, the catalyst 0.4-Bi2Sn2O7/Ag/Ag3PO4 with m(Bi2Sn2O7):m(Ag3PO4)= 0.4:1.0 mass ratio has the highest Rhodamine B degradation efficiency of 98.2% in 80 min, which is 8.3 and 4.2 folds higher than that of Bi2Sn2O7 and Ag3PO4, respectively. Besides, Bi2Sn2O7/Ag/Ag3PO4 possessed the effectively degradation of xylenol orange (XO) and Cr (Ⅵ). The results of the radical scavengers reveal that h+ and·O2− act as the main photocatalytic reactive specie. The photocatalytic mechanism over Z-scheme Bi2Sn2O7/Ag/Ag3PO4 has been proposed based on the experimental results together with the ultraviolet photoelectron spectroscopy (UPS) analysis and scavenger reactions.

ENHANCE A PHOTOCATALYTIC ACTIVITY ON Ag3PO4 BY Ag\Ag3PO4 COMPOSITES

In this study, we investigated the formation and influence of Ag particles on the physical properties and photocatalytic performance of Ag3PO4 photocatalysts when Ag particles adhered to the Ag3PO4 surface. The material is prepared by a simple precipitation method with illumination. The properties of the materials were investigated by X-ray diffraction (XRD), Raman scattering, scanning electron microscopy (SEM), UV-vis absorption, and the photocatalytic ability to decompose organic solutions. The results show the vibrational change of the [PO4] group in the structure presented in the Raman scattering spectrum highest RhB decomposition. The experimental results indicated that the Ag\Ag3PO4 showed highly efficient and stable photocatalytic activity under visible light irradiation. The Ag\Ag3PO4 sample with the Ag+\PO43- the ratio of 3.6\1 gave efficiency when stimulated with visible light of Xenon lamps. This sample degraded almost completely to RhB in 10 ppm solution after 15 min of illumination, with a decomposition rate of 0.241 min-1.

High photocatalytic activity of Ag/Ag3PO4:W heterostructure formed by femtosecond laser irradiation

In this work, the W-doped Ag3PO4 was prepared by the chemical coprecipitation method and irradiated with a femtosecond laser (FL). The successful formation of the Ag/Ag3PO4:W heterostructure was confirmed by XRD analysis. A higher structural disorder in the [PO4] clusters was observed for the FL irradiated sample (Ag3PO4:W-FL), indicating the formation of Ag metallic from the Ag3PO4 structure. The photocatalytic activity of the samples was studied by photodegradation of rhodamine B under visible light irradiation. The formation of Ag nanoparticles on the surface of Ag3PO4:W led to a degradation rate constant 3.54 times higher than the nonirradiated sample. This higher photocatalytic activity was related to the surface plasmon resonance effect of the Ag metallic, which acts by capturing photoexcited electrons from the Ag3PO4:W, avoiding the recombination of electron-hole pairs, and thus improving the photocatalytic activity.

Construction of Cu-Fe bimetallic oxide/biochar/Ag3PO4 heterojunction for improving photocorrosion resistance and photocatalytic performance achieves efficient removal of phenol

Ag3PO4 has an excellent visible light response, but its serious photocorrosion has limited its application in environmental remediation. Here, we constructed a ternary heterojunction photocatalyst (CuFe2O4/Biochar/Ag3PO4) to inhibit its photocorrosion and enhance photocatalytic activity. Notably, the composite catalyst (0.5 g/L) thoroughly degraded phenol (20 mg/L) at 18 min, and its apparent kinetic constant is fivefold that of pure Ag3PO4. The analysis of XPS, XRD, and cyclic degradation experiments confirmed that the photocorrosion of the heterojunction photocatalyst was significantly suppressed. The enhanced photocorrosion resistance of Ag3PO4 can be ascribed to the rapid transfer and consumption of photoelectrons on the Ag3PO4 surface by biochar and CuFe2O4, thereby avoiding photocorrosion. Especially, Ag3PO4 as a hole-rich region can protect Ag+ from being reduced. DFT calculations further revealed the electron transfer and anti-photocorrosion mechanism of Ag3PO4. The photogenerated O2– and h+ played a major role in phenol degradation. A possible degradation pathway was proposed by DFT calculations and GC–MS analysis. This study provides a novel ternary heterojunction photocatalyst to improve the catalytic performance and photocorrosion resistance of Ag3PO4.

The enrichment of silver ions in Ag3PO4 through the morphology changes and their photocatalytic activities

The Ag3PO4 photocatalyst has been developed to degrade the organic pollutant due to its highly active responsive under visible light irradiation. The properties of Ag3PO4 may depend on design and preparation. Starting materials and co-precipitation conditions would significantly affect the properties of the product. The controlled defect of this photocatalyst may lead to improve catalytic activity. Here, the unique properties of phosphate deficiency in Ag3PO4 were created using the starting material of KH2PO4 and AgNO3 under a mixed solvent of water and ethanol. AgNO3 solution with the ethanol percentages of 0%, 25%, 50%, 75% and 90% was added to KH2PO4 aqueous solution. The photocatalysts were characterized using XRD, DRS, SEM, and XPS. The changes in morphology can be observed from the tetrahedral to the sphere which has smaller particles. The increased atomic ratio of Ag/P and Ag/O suggests that the silver ion enrichment in Ag3PO4 has been created. The activity of Ag3PO4 for Rhodamine B elimination increased by 4.3 times higher compared to that of the pristine Ag3PO4. The enhanced photocatalytic activity might be caused by the smaller particle size and higher silver ion content on the surface of Ag3PO4.

The Surface Modification of Ag3PO4 using Tetrachloroaurate(III) and Metallic Au for Enhanced Photocatalytic Activity

The improvement of Ag3PO4 photocatalytic activity was successful by incorporating tetrachloroaurate(III) (AuCl4−) and metallic Au on the surface of Ag3PO4. The photocatalysts were synthesized using the coprecipitation and chemisorption method. Coprecipitation of Ag3PO4 was carried out under ethanol-water solution using the starting material of AgNO3 and Na2HPO4.12H2O. AuCl4− ion and metallic Au were incorporated on the surface of Ag3PO4 using a chemisorption method under auric acid solution. The photocatalysts were characterized using XRD, DRS, SEM, and XPS. The AuCl4− ion and metallic Au were simultaneously incorporated on the Ag3PO4 surface. The high photocatalytic activity might be caused by increasing the separation of hole and electron due to capturing photogenerated electrons by metallic Au and Au(III) as electron acceptors. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Surface modification of Ag3PO4 using the alginate for highly active photocatalyst under visible light irradiation

Surface modification of Ag3PO4 using alginate has been successfully synthesized. Ag3PO4 was prepared by precipitation method using CaHPO4/hydroxyapatite composite as a source of phosphate ion and AgNO3 ethanol solution. Alginate was introduced on the surface of Ag3PO4 under the chemisorption method. Products were analyzed using XRD, DRS, PL spectra, FTIR, SEM, TEM, and XPS. A small band edge absorption at 729 nm was created after surface modification using alginate. XPS analysis showed that the binding energy shifts of 0.3 eV and 0.5 eV were observed after alginate treatment for Ag3d and P2p respectively indicating that the alginate was successfully chemically bound to the Ag3PO4 surface. The alginate-modified Ag3PO4 photocatalyst showed much higher photocatalytic activity than pure Ag3PO4. The high activity is caused by the formation of conjugates that can act as electron donors under visible light irradiation.

Bioactive Ag3PO4/Polypropylene Composites for Inactivation of SARS-CoV-2 and Other Important Public Health Pathogens.

The current unprecedented coronavirus pandemic (COVID-19) is increasingly demanding advanced materials and new technologies to protect us and inactivate SARS-CoV-2. In this research work, we report the manufacture of Ag3PO4 (AP)/polypropylene (PP) composites using a simple method and also reveal their long-term anti-SARS-CoV-2 activity. This composite shows superior antibacterial (against Staphylococcus aureus and Escherichia coli) and antifungal activity (against Candida albicans), thus having potential for a variety of technological applications. The as-manufactured materials were characterized by XRD, Raman spectroscopy, FTIR spectroscopy, AFM, UV–vis spectroscopy, rheology, SEM, and contact angle to confirm their structural integrity. Based on the results of first-principles calculations at the density functional level, a plausible reaction mechanism for the initial events associated with the generation of both hydroxyl radical •OH and superoxide radical anion •O2– in the most reactive (110) surface of AP was proposed. AP/PP composites proved to be an attractive avenue to provide human beings with a broad spectrum of biocide activity.

Z-scheme Fe2(MoO4)3/Ag/Ag3PO4 heterojunction with enhanced degradation rate by in-situ generated H2O2: Turning waste (H2O2) into wealth (•OH)

Ag3PO4-based photocatalysts have been deeply studied in environmental remediation; however, two problems limited their further application: photocorrosion and quenching effect by in-situ generated H2O2. To addressed these two questions simultaneously, Fe2(MoO4)3 was coupled with Ag3PO4 to construct Z-scheme Fe2(MoO4)3/Ag/Ag3PO4 heterojunction driven by internal-electric-field. The rhodamine B degradation rate of heterojunction was 254 and 7.0 times higher than those of Fe2(MoO4)3 and Ag3PO4, respectively. The outstanding photoactivity was due to the high visible-light harvest, low interface resistance, high separation efficiency of charge carriers, long lifetime of hole (h+) and electron (e-), well-preserved oxidation potential of h+, and especially photocatalytic produced H2O2 inside the system. The in-situ generated H2O2 was fully activated to be •OH on the Fe2(MoO4)3 surface via a Fenton reaction, leading to the elimination of quenching effect on h+ and e-, and generation of more •OH. Additionally, in Z-scheme heterojunction, e- transferred from Ag3PO4 to Fe2(MoO4)3, avoiding the accumulation on Ag3PO4 surface, and hence suppressing the photocorrosion. As a result, 91.2% of degradation efficiency remained after 5 cycles. This paper provides a new method to simultaneously increase the degradation rate by utilizing the in-situ generated H2O2 and improve the stability of Ag3PO4 via constructing a Z-scheme heterojunction.

CaAl2O4: Eu2+, Nd3+ anti-corrosive coating and its afterglow - Catalytic process

This work provided an efficient strategy for degradation of organic pollutants in a bad water environment around-the-clock. In this study, a novel afterglow - catalytic system was developed, comprising Ca0.985Al2O4: 0.01Eu2+, 0.005Nd3+ coating as the light source and Ag3PO4 and Pt/Ag3PO4 as the photocatalysts. The results showed that Ca0.985Al2O4: 0.01Eu2+, 0.005Nd3+ emited a blue-violet long afterglow with the primary peak at 440 nm, which could be effectively absorbed by Ag3PO4 and Pt/Ag3PO4 photocatalysts to achieve photocatalytic function in the dark. The afterglow - catalytic activity was enhenced through modifying Nano - Pt particles on the surface of Ag3PO4. More interestingly, the chemical stability of Ca0.985Al2O4: 0.01Eu2+, 0.005Nd3+ phosphor was improved immensely by coating silicone acrylic emulsion, which could resist strong corrosion from water, acid and alkali solution for a long period.

Ag nanoparticles decorated[formula omitted]with enhanced field emission

Tetrapod Ag3PO4 was synthesized by a simple hydrothermal method, and ultraviolet lamp irradiation was used to precipitate Ag on the surface of Ag3PO4 to form Ag/Ag3PO4 metal-semiconductor structure. The field emission performance of Ag/Ag3PO4 composite was studied. Compared with pureAg3PO4, precipitated Ag changed the morphology of the surface of Ag3PO4, effectively reducing the field emission turn-on field from 5.9 Vμm-1 to 2.3 Vμm-1, and the field enhancement factor was increased from 1012 to 1923. After Ag3PO4 was wrapped by Ag nanoparticles, the formed metal-semiconductor structure produced ohmic contact, accelerating the transfer of electrons on the interface and enhancing the field emission performance. Ag nanoparticles protected Ag3PO4 from photodegradation, which effectively improved the stability of Ag3PO4 and the field emission enhancement mechanism was analyzed by the classical F-N theory.

RETRACTED: The synthesis of Bi12GeO20/Ag3PO4 nanowire composite for increased photocatalytic activity and decreased electron/hole recombination

Abstract Bi12GeO20 nanowires uniformly decorated with ultrafine Ag3PO4 nanoparticles (Bi12GeO20/Ag3PO4) were synthesized. The Bi12GeO20/Ag3PO4 nanowire composite with 10 wt% of Ag3PO4 exhibited significantly improved photocatalytic performance and excellent stability over pure Bi12GeO20, Ag3PO4 and other composites, with the RhB dye decomposition efficiency reaching 94.2%. The electrochemical and photocurrent response measurements suggested that the electrons generated in Bi12GeO20 during the photocatalytic reaction could be quickly transferred to the Ag3PO4 surface, resulting in increased electron/hole separation. The trapping experiments with different scavengers and ESR results revealed that holes and ·O2− were the dominant active species for the photocatalytic decomposition of RhB, and the presence of Ag3PO4 was beneficial to generate more ·O2− species and enlarge the active surface area, leading to significantly improved photocatalytic performance. The presented photocatalyst heterostructure composed of appropriate semiconductor nanoparticles and one-dimensional nanowires in this study could be extended to the construction of other photocatalysts for a wide variety of photocatalytic applications.

Construction of p-n type Ag3PO4/CdWO4 heterojunction photocatalyst for visible-light-induced dye degradation

Regarding the high stability of Ag3PO4 and CdWO4, their valence band and conduction band energy levels match each other, a novel p-n type Ag3PO4/CdWO4 heterojunction photocatalyst was synthesized by conventional hydrothermal strategy, and analyzed by PXRD, SEM TEM and XPS, respectively. The corresponding results suggested that the nanorods of CdWO4 were successfully intergrown on the surface of Ag3PO4. The as-synthesized Ag3PO4/CdWO4 exhibited enhanced photocatalytic performance and reusability than that of two independent precursors via visible-light-induced photodegradation of Rhodamine B (RhB). The improved photocatalytic performance may due to expanded visible-light response range and enhanced the efficiency of carrier pairs separation induced by the adjustment of band-gap in p-n type Ag3PO4/CdWO4 heterojunction. Moreover, a putative photocatalytic mechanism of such heterojunction in degradation with dye was proposed.