Photodegradation Of Rhodamine B Research Articles

Two new coordination polymers: crystal structures and photodegradation of the organic dye RhB

The solvothermal assemblies of a silicon-centered tetrahedral ligand as a principal building block, an N-donor ancillary ligand, and the corresponding metal salts yield two new transition metal coordination polymers (CPs), [Zn3(OH)(H2O)3L(ttb)]·3H2O (1) and [Co3(OH)(H2O)2L(ttb)(DMF)2]·2H2O (2) [H4L = 4,4',4'',4'''-silanetetrayltetrabenzoic acid, ttp = 1-(tetrazo-5-yl)-4-(triazo-1-yl)benzene, DMF = N,N-dimethylformamide]. Photocatalytic test results indicate that 1 and 2 can serve as excellent photocatalysts for Rhodamine B (RhB) degradation.

Anthraquinone and its Derivatives as a Recyclable Photocatalyst for Efficient Photocatalytic Degradation of Rhodamine B in Water under Visible Light

AbstractThis study presents findings that suggest it is possible to fine‐tune and enhance the optical properties of anthraquinone (AQ) and its photocatalytic performance in the degradation of rhodamine B (RhB) at the molecular level through varying its keleton substituents. Specifically, the electron‐withdrawing substituent demonstrates a more pronounced improvement effect compared to the electron‐donating substituent. Out of the several compounds, 2‐carboxyanthraquinone (AQ−COOH) exhibits the highest photocatalytic activity. This is due to its ionization in water, generating H+ ions that enhance the destruction of RhB through photodegradation. After 30 min of exposure to visible light, the degradation rate of RhB reaches an impressive 99.9 %. It is noteworthy that a hydrochloric acid solution with a concentration of 0.5 mmol ⋅ L−1 has a considerable promoting impact on the photodegradation of RhB catalyzed by AQ−COOH, and that the total degradation of RhB can be accomplished in 15 min. In addition, AQ−COOH also has good applicability for the degradation of tetracycline, methylene blue, and methyl orange. As a recyclable solid catalyst, the catalytic activity of AQ−COOH remained mostly unchanged after being used five times. Additionally, AQ−COOH did not undergo degradation when exposed to visible light, indicating its excellent stability in the process of catalyzing RhB degradation. According to quenching experiments and EPR spectrum characterizations, the photo‐generated active species oxygen vacancies (h+), photogenerated electrons (e−), superoxide free radicals (O2⋅−), singlet oxygen (1O2) and hydroxyl radical (•OH) are involved in the hypothesized photo‐catalytic degradation mechanism.

How to design plasmonic Ag/SrTiO3 nanocomposites as efficient photocatalyst: Theoretical insight and experimental validation

An integrated theoretical-experimental investigation is performed to understand the photocatalytic and optical properties of Ag/SrTiO3 nanocomposite (Ag/STO). Theoretical investigation reveals that the catalytic activity of Ag/STO is increased when Ag particle size is smaller, while the opposite correlation is observed for its visible-light absorbance efficiency. These insights suggest that efficient Ag/STO photocatalyst needs to be balanced between the active interfacial site density and visible-light absorbance intensity by carefully controlling the Ag dosage. Furthermore, reactive oxygen species that are responsible for the oxidative degradation of organic pollutant on Ag/STO could be identified from Density Functional Theory (DFT) calculations. Comprehensive experiments are carried out using Rhodamine-B (RhB) photodegradation to test the activity of Ag/STO in wastewater treatment application and excellently validate those theoretical predictions. Over series of synthesized Ag/STO composites with different Ag contents, the optimum 1 % wt. Ag loading has the highest 92.8 % efficiency in RhB photodegradation after 1 hour of light irradiation. Trapping experiments also confirm the crucial role of O2 and OH species, which was predicted from DFT calculations, as the primary oxidizing agents for the degradation of RhB. This work provides a useful framework to develop novel plasmonic nanocomposites for other photocatalytic applications.

Enhanced photocatalytic activity of (In–Sr–P) tridoped TiO2/Bi2O3 composite loaded on mesoporous carbon: A facile sol-hydrothermal synthesis approach

Photocatalysis attracted attention as a promising technique for wastewater treatment, especially for water contaminated with organic pollutants such as dyes. However, designing a suitable photocatalyst with a simple procedure and high catalytic performance is still a big challenge for large-scale production. Here, indium-strantiom and phosphorous tridoped Bi2O3–TiO2 composite loaded on mesoporous carbon (ISP–TiO2/Bi2O3@C) was prepared via the sol-hydrothermal method. The as-prepared ISP-TiO2/Bi2O3@C displayed a mesoporous structure with a BET surface area of 84.804 m2 g−1. The photocatalytic activity of the ISP-TiO2/Bi2O3@C composite was investigated toward the degradation of rhodamine B (RB) under exposure to UV, and sunlight. It was found that ISP-TiO2/Bi2O3@C photocatalyst exhibited superior photocatalytic activity against photodegradation of RB under UV light and sunlight irradiation with a degradation percentage of 99.12, and 95.71 %, respectively. In addition, ISP-TiO2/Bi2O3@C composite displayed a distinguished recycling ability after the fifth recovery cycle, indicating a promising candidate for photocatalytic applications under UV light and sunlight. Consequentially, the higher photocatalytic activity of ISP-TiO2/Bi2O3@C under sunlight irradiation implies that the sol-hydrothermal method is promising for the preparation of efficient and low-cost TiO2-based photocatalysts for the photodegradation of various environmental pollutants.

Ternary Nanocomposites of Copper/graphitic‐Phase Carbon Nitride/rare‐Earth Pentaborate for Photocatalytic Applications Under Simulated Sunlight Illumination

AbstractA wide variety of borate materials are emerging as photocatalysts. Usually, the borates possess a large bandgap which limits their absorption of visible light, and the strategy of preparing nanocomposites is an effective way to enhance the absorption of light. X‐ray powder diffraction, infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy were used to show that a three‐component nanocomposites was successfully prepared. For the photo‐degraded reactions of rhodamine B(RhB) and doxycycline hydrochloride(DH), the optimum composition of the ternary composite is a molar ratio of Gd0.9Ce0.1B5O9(GCBO) and g‐C3N4(CN) of 7 : 93, besides the mass of Cu is 2 % of the sum of the above two masses, and the ternary composite is abbreviated as 2Cu/CN@GCBO‐7. The kinetic constant for the photodegradation of RhB of sample 2Cu/CN@GCBO‐7 is 0.0580 min−1, which is 3.6 and 3.8 times that of non‐composite CN and GCBO. The mechanism postulated by free radical quenching experiments suggests that the importance of the three radicals is hole >⋅OH>⋅O2− in the photodegradation reaction. In addition, the kinetic constant for the photodegradation of DH of sample 2Cu/CN@GCBO‐7 is 0.0018 min−1, and the sample 2Cu/CN@GCBO‐7 has a hydrogen evolution rate of 11.8 μmol/h/g.

Magnetically separable Z-scheme ZnFe2O4/MoS2 photocatalyst for boosting photo-Fenton degradation activity by a hole-mediated mechanism

The development of high-efficiency and robust photocatalysts is imperative and challenging in advanced oxidation processes (AOPs). Herein, magnetically separable ZnFe2O4/MoS2 photocatalyst was prepared by a simple hydrothermal method. The degradation characteristics of several organic pollutants (rhodamine B (RhB), methyl orange, methylene blue, and antibiotic tetracycline) were investigated with/without the addition of H2O2 under visible light irradiation. It is found that the synergistic effect of Z-scheme ZnFe2O4/MoS2 photocatalyst and photo-fenton-like reaction promotes the decomposition of H2O2, accelerates the separation efficiency of photogenerated electrons and holes, and thus improves the photocatalytic activity. The RhB photo-degradation of the constructed Z-scheme ZnFe2O4/MoS2 (96.3%) photocatalyst in the absence of H2O2 for 100min is better than that of MoS2 (74.8%) and ZnFe2O4 (6.2%), with a rate constant of 0.0332min-1. The slight amount of H2O2 boosts the photocatalytic performance significantly. Its degradation rate is 98.6% within 8min with the rate constant of 0.396min-1, 12 times higher than that of ZnFe2O4/MoS2 photocatalyst without H2O2. The magnetic separation, recycling stability and neutral solution process are also confirmed in ZnFe2O4/MoS2 system, indicating the enormous potential of this photocatalyst in environmental remediation and waste water treatment. The hole-mediated oxidation mechanism has been proposed instead of conventional active radicals of •OH based on the free radicals capture and electron spin resonance experiments. MoS2 plays a crucial role in facilitating the H2O2 decomposition and realizing the conversion circulation from Fe3+ to Fe2+ by the redox cycling as a co-catalyst. This study provides insights into the photocatalytic mechanism of Z-scheme photo-Fenton heterojunction photocatalysts, conducive to the development of high-efficient and stable photocatalysts in AOPs.

Construction of novel S-defects rich ZnCdS nanoparticles for synergistic visible light assisted photocatalytic degradation of rhodamine B: Insights into mechanism, pathway and by-products toxicity evaluation

The contamination of wastewater by azo dyes indicates serious environmental risks. Currently, industries worldwide use approximately 700,000 tons of these dyes annually, making their removal a significant challenge. In photocatalysis research, a prominent area of dedication to the advancement of visible light photocatalysis aims to achieve superior performance in overall activity. In this study, we fabricated ZnCdS nanoparticles (NPs) via a simple co-precipitation strategy, and sulphur (S)-defect-rich ZnCdS NPs (D-ZnCdS) were created through the ball milling method. These S-defect nanoparticle (NPs) catalysts were utilized for rhodamine B (RhB) dye photocatalytic degradation experiment. (XRD) X-ray diffractometer, X-ray photoelectron spectroscopy (XPS), surface-enhanced Raman spectroscopy, and photoluminescence (PL) spectroscopy characterization studies explained the induced S-defect rich in D-ZnCdS NPs. Further, the morphological, band gap determination, and photogenerated charge carrier recombination efficiency were studied using different analytical and spectroscopic characterization techniques. The Brunauer-emmett-teller (BET) results indicate the increased surface area of D-ZnCdS NPs thereby providing more active sites. The photocatalytic degrading efficiency of D-ZnCdS over RhB explains the complete degradation of pollutants within 260 min. This enhancement in the catalytic process is attributed to the increased absorption of photon energy from the visible light and large defect-rich active sites. Further, the involvement of hydroxyl (*OH) and superoxide radicals (O2*-) in the degradation of RhB along with the presence of sulphur defects, significantly improves the charge transfer in ZnCdS NPs. The involvement of certain factors like pH, ions, NCs catalyst and different RhB concentrations on RhB degradation was investigated. Additionally, D-ZnCdS NPs showed stable degrading capability even after six consecutive cycles of catalytic RhB degradation. The by products formed during the RhB photodegradation experiment were identified using Gas chromatography-mass spectrometer (GC-MS) analysis, and toxicity in fish, daphnia, and algae was examined using the Ecological structure-activity relationships (ECOSAR) program. From the above findings, the current research work provides a new strategy for utilizing defect-engineered D-ZnCdS NPs as a promising catalyst for various environmental remediation applications and paves a ways for manufacturing innovation.

Visible-light-driven BiOI and GO/BiOI photocatalysts for organic pollutants degradation and hydrogen production using low power sources

BiOI and (3 wt%)GO/BiOI visible-light-driven photocatalysts were obtained by a one-pot solvothermal method and successfully applied to the degradation of single and binary dye solutions of rhodamine B (RhB) and methylene blue (MB) and H2 production using very low-power sources. The GO/BiOI with hierarchical flower morphologies exhibited the highest activity, achieving RhB and MB photodegradation percentages (%Xdye) of 100% and 80%, respectively, in 240 min employing a simple 19 W white LED array. Furthermore, GO/BiOI dosage and RhB initial concentration play an essential role in dye degradation, and scavenger assays confirmed that holes and superoxides are the main species causing RhB oxidation. TOC analysis determined an efficiency of 70%, and after three uses, the GO/BiOI attained a %XRhB of 84%. The H2 evolution was performed under 2 W UV light, yielding 323.25 μmol/h∙g of H2 for BiOI, and the addition of GO nanosheets increased the photoactivity of GO/BiOI up to 63% (509.61 μmol/h∙g). The catalytic activity of GO/BiOI is superior to values reported in the literature considering nominal power consumption (kWh) vs. efficiency of RhB degradation or H2 production.

Excellent performance of BiOI/AgEuW2O8 S-Scheme heterojunction for photocatalytic degradation of contaminants under visible light: Experimental and computational studies

A series of xBiOI/AgEuW2O8 (BIAEW-x, x = 1, 2, 3) photocatalysts were prepared by hydrothermal method, further applied for photocatalytic degradation of organic contaminants under the visible light irradiation. The microstructure and photocatalytic properties of the as-synthesized samples were determined by various techniques such as XRD, SEM, TG-DTG, XPS, UV–Vis, ESR, and N2-adsorption. Heterojunction was formed within transition area between BiOI and AgEuW2O8, and the special structure was further validated by the results of XRD and XPS. It was found the composite with 2:1 ratio of BiOI/AgEuW2O8 possessed the highest activity of 99.48 % rhodamine B (RhB) photodegradation which was observed under the optimized conditions (3 h, pH = 5, 60 mg, 30 mg/L). This may be due to the maximum existence of BiOI/AgEuW2O8 heterojunction within the solid, which promotes the generation of the active species during the photocatalytic process. Besides, the newly-formed O–Ag bonds bridging the interface between BiOI (1 0 2) and AgEuW2O8 (0 0 4) were also confirmed according to the DFT calculations, and the electrons and holes increased largely for the interface structure. Moreover, the photodegradation process of RhB promoted by xBiOI/AgEuW2O8 follows first-order kinetic law. Furthermore, the trapping experiments were respectively conducted via addition of different trapping reagents, of which the holes were confirmed as the key active species on photodegradation of RhB over BIAEW-2 under visible light irradiation.

Carbon nitride coupled with carbon nanohorns for improved photocatalytic hydrogen production and dyes degradation

In the present study we attempted to develop photoactive nanocomposites via the facile coupling of carbon nitride (CN) with single walled carbon nanohorns (CNHs). Photocatalytic activity was evaluated for the degradation of Rhodamine B (RhB) and the production of H2. The CNHs content noticeably affected the photoactivity of the nanocomposites and the best performing material exhibited a 3-fold increase in photocatalytic H2 production compared to pristine CN using 1 wt% Pt as co-catalyst. A systematic study was undertaken to explain the mechanistic aspects of the photo-reaction process. The active species responsible for the photodegradation of RhB were identified using reference reactions. Such species were further studied using in-situ spin-trap EPR experiments. Photoluminescence and time-resolved fluorescence decay kinetics suggested faster transfer of photogenerated electron/hole pairs resulting in reduced charge recombination phenomena in the nanocomposites. The combined photocatalytic application and characterization of the prepared materials revealed that the promotion of the redox reactions in based on improvements on the charge separation efficiency.

Template assisted hydrothermal synthesis of bismuth vanadate for Rhodamine B photodegradation

Developmental and technological activities result in uncontrollable release of synthetic dyes into water reservoirs posing potential threat to flora and fauna. Thus, the development of suitable process to treat these waste effluents is urgently needed. Herein, a facile technique was employed to synthesize bismuth vanadate (BiVO4) by incorporating Chitosan (Cs) and Triblock pluronic 123 (P) as directing agents through the hydrothermal process and its efficacy as a photocatalyst was tested for Rhodamine B (RhB) photodegradation. It is noteworthy that the use of Cs as template during the synthesis of BiVO4 had not been previously documented. The synthesized materials were subject to a comprehensive array of characterization techniques, including XRD, FTIR, UV–visible diffuse reflection, SEM, TEM, N2 adsorption isotherm, and XPS analyses. The outcomes revealed that the synthesized catalysts have a monoclinic scheelite structure and displayed an irregular morphology. In addition, the particle size decreased remarkably with the use of Cs. The XPS revealed that the templates have a major influence on the surface charge of the material, as revealed by point of zero charge (pHPZC) analysis. Notably, BiVO4-Cs exhibited the highest specific surface area (SSA: 12.27 m2/g) among them. The synthesized photocatalysts exhibited high catalytic stability. Additionally, the photocatalysts showed excellent RhB photodegradation performance of 94.2 and 64.4 % under UV-B and visible light illumination, respectively.

Characterization and the Effect of Different Parameters on Photocatalytic Activity of Montmorillonite/TiO2 Nanocomposite under UVC Irradiation

This study aimed to modify montmorillonite (MMT) with titanium dioxide (TiO2) by wet stirring method combined with ultrasonic to form MMT/TiO2 nanocomposite and used as a photocatalyst in the removal of organic dye rhodamine B (RhB). The characteristics of the synthesized samples were analyzed by methods such as energy-dispersive X-ray spectroscopy (EDX), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and UV-Vis diffuse reflectance spectra (UV-Vis DRS). The degradation of RhB was carried out for 210 min under UVC irradiation, and the decolorization efficiency of RhB was evaluated by UV-vis spectroscopy. The results show that the TiO2 anatase nanoparticles are randomly distributed on the surface or the space between the MMT sheets to form a house-of-card structure. After 210 min of exposure under a UVC light source, the decolorization efficiency reached 91.5% for the solution with pH = 6.8, photocatalyst content 0.1 g/L, initial concentration RhB 10 mg/L, and UVC power 15 W. Liquid chromatography–mass spectrometry (LCMS) identified the degradation intermediates that MMT/TiO2 successfully cleaved the chromophore structure and formed more minor broken-ring by-products. The influence of operating parameters on RhB removal efficiency, including solution pH, photocatalyst content, initial dye concentration, inorganic, and organic scavengers, was studied. In addition, the kinetic modeling study shows that the RhB photodegradation reaction is consistent with the Langmuir-Hinshelwood first-order kinetic model.

Photocatalytic degradation of rhodamine B over Z-scheme photocatalyst BiFeO3/3DOM-TiO2-x in a fixed-bed reactor

In this work, a Z-scheme BiFeO3/3DOM-TiO2-x photocatalyst was synthesized using a hydrothermal method and extensively evaluated for its photocatalytic capabilities in the rhodamine B (RhB) degradation within a fixed-bed reactor. The results demonstrated the synergistic effects of enhanced visible light absorption, a Z-scheme charge transfer mechanism, oxygen vacancies, and unique three-dimensional ordered macropore structure, which collectively enhance the photocatalytic activity of BiFeO3/3DOM-TiO2-x. The active groups responsible for RhB degradation included hydroxyl radicals (•OH), hole (h+), and reactive superoxide radical (•O2−), of which •O2− played a predominant role in RhB photodegradation. A kinetic model of dye degradation in a fixed-bed reactor was proposed, providing a realistic description of RhB degradation.

Enhancing the Photocatalytic Activity and Luminescent Properties of Rare-Earth-Doped CeO2 Nanoparticles

Our study is focused on the structural and morphological characteristics, optical behaviour and photocatalytic properties of undoped and 5 at% Eu3+-, Gd3+- and Y3+-doped CeO2 nanoparticles prepared by a green hybrid sol-gel combustion method. Several techniques such as X-ray diffraction powder (XRD), Transmission Electron Microscopy (TEM), UV-Vis spectroscopy, Photoluminescence spectroscopy (PL) and Electron Paramagnetic Resonance (EPR) have been used to investigate the obtained samples. Moreover, the correlation between the characteristics and properties has been studied. The nanoparticles observed by TEM exhibit a pseudo-spherical shape, except for Y3+-doped CeO2, which presents an acicular shape. The average size of undoped and rare-earth-doped CeO2 nanoparticles is below 10 nm, in good agreement with the calculations performed based on XRD analyses. From UV-Vis analyses it has been deduced that with doping the band gap energy decreases, which shows that additional levels are introduced by doping into the CeO2 band gap. The EPR spectra evidence similar behaviour for all doped samples. The photocatalytic activity was evaluated by the degradation of rhodamine B (RhB) under UV light irradiation. The photodegradation mechanism has been studied in depth based on the formation of electron-hole pairs, and to evidence the reactive oxygen species, ESR coupled with spin-trapping experiments was performed. In the case of Y-doped CeO2 nanoparticles, the generation of both •OOH and •O2− radicals involved in RhB photodegradation was highlighted.

Synthesis of a visible light driven Ag–CeO2/g-C3N5 heterojunction with efficient photocatalytic performance for organic dyes

Wastewater containing organic dyes is harmful to the ecological environment and human health. Graphitic carbon nitride (g-C3N5) is suitable for the photocatalytic degradation of organic dyes, but its photocatalytic activity is low due to several drawbacks. A series of Ag–CeO2/g-C3N5 composites with different morphologies of Ag–CeO2 have been prepared in order to improve the photocatalytic activity of g-C3N5. The photocatalytic activities of the Ag–CeO2/g-C3N5 composites were investigated using rhodamine B (RhB) as the target pollutant. When compared with Ag–CeO2 spheres and g-C3N5, the charge separation efficiency and photocatalytic activity of the Ag–CeO2/g-C3N5 heterostructure were significantly improved. The photodegradation rate of RhB using 50 wt% Ag (1.50)-CeO2(sphere)/g-C3N5 was 96.5 %, while pure g-C3N5 and Ag (1.50)-CeO2 spheres was 30.8 and 9.9 %, respectively. This was attributed to the synergistic effect of the heterojunction comprised of Ag, CeO2, and g-C3N5. As an electronic medium, Ag transfers electrons between g-C3N5 and CeO2, which can promote electron-hole separation and improve the photocatalytic activity. The 50 wt% Ag (1.50)-CeO2(sphere)/g-C3N5 composites also had fair photocatalytic stability and ·O2− plays a dominant role in the RhB photodegradation process. In addition, the photocatalytic mechanism of 50 wt% Ag (1.50)-CeO2(sphere)/g-C3N5 has also been described.

A floating photocatalytic fabric integrated with a AgI/UiO-66-NH2 heterojunction as a facile strategy for wastewater treatment.

With an increased need of wastewater treatment, application of photocatalysts has drawn growing research attention as an advanced water remediation strategy. Herein, a floating photocatalytic fabric in a woven construction was developed for removal of Rhodamine B (RhB) in water. For an efficient photocatalytic reaction, AgI nanoparticles were grown on the surface of UiO-66-NH2 crystals in a layered structure, forming a heterojunction system on a cotton yarn, and this was woven with polypropylene yarn. The floating photocatalyst demonstrated the maximized light utilization and adequate contact with contaminated water. Through the heterojunction system, the electrons and holes were effectively separated to generate reactive chemical species, and this eventually led to an enhanced photocatalytic performance of AgI/UiO@fabric reaching 98% removal efficiency after 2 hours of irradiation. Photodegradation of RhB occurred mainly by superoxide radicals and holes, which were responsible for de-ethylation and decomposition of an aromatic ring, respectively. The kinetics of the photocatalytic reaction suggested that circulation of solution by stirring affected the photocatalytic removal rate. The recycle test demonstrated the potential long-term applicability of the developed material with structural integrity and catalytic stability. This study highlights the proof-of-concept of a floating photocatalytic material for facile and effective water remediation with repeated usability.

Enhanced photocatalytic efficiency of porous ZnO coral-like nanoplates for organic dye degradation.

ZnO nanomaterials have been extensively used as photocatalysts for the removal of pollutants in aqueous environments. This study explores the enhanced photocatalytic performance of porous ZnO coral-like nanoplates synthesized via a one-pot wet-chemical method and subsequent annealing treatment. Characterization through scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), powder X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy, photoluminescence (PL) spectroscopy, and Brunauer-Emmett-Teller (BET) measurements confirmed the nanoplates' porous structure, single-crystal structure, 100 nm thickness, and 80 nm pore size. These unique structural characteristics of the ZnO coral-like nanoplates enabled effective photodegradation of the organic dye rhodamine B (RhB) under visible light irradiation. Under simulated sunlight, the ZnO photocatalyst exhibited exceptional performance, achieving a 97.3% removal rate of RhB after 210 minutes of irradiation. The prepared ZnO photocatalyst also showed remarkable photostability and regeneration capability for RhB photodegradation with a decreased efficiency of less than 15% after eight testing cycles. The potential mechanism of the ZnO photocatalyst toward RhB degradation was also studied and is discussed in detail.

Systematic exploration of defect-rich 2D nanopetal assembled 3D ZnO nanoflowers for improved photocurrent generation and photocatalytic performance

Zinc Oxide (ZnO) stands as a highly significant metal oxide semiconductor with a large band gap of (3.2 eV), showcasing multifaceted properties. Significant findings of this study, designate the successful fabrication of 3D nanoflowers (NFs) with a specialized ZnO nanoarchitecture through a facile polyol process, considered by a notable presence of defect sites, as a photocatalyst for the deterioration of Rhodamine B (RhB). All ZnO NFs display increased absorption and a distinctive shift towards longer wavelengths, indicating a red shift phenomenon. Raman scattering, photoluminescence (PL), X-ray photoelectron spectroscopy (XPS), and electron spin resonance (EPR) unveiled that, the ZnO/24 hr, exhibited a notable abundance of defect states. The Brauner–Emmett–Teller (BET) analysis shows surface area of 55.14 m2g−1 for ZnO/24 hr resulted in a subsequent augmentation of the concentration of surface defects potentially enhancing the RhB photodegradation efficiency of 98%, surpassing the performance of other ZnO NFs samples, with a kinetic rate of 0.0638 min–1 under sunlight irradiation and better photocurrent response that improves the photogenerated separation of charge carriers. Hence, the findings from this investigation will offer novel perspectives for enhancing the photocatalytic and photoelectrochemical attributes of ZnO NFs grown over different durations.

Ag3PO4/g-C3N4/Zn3(PO4)2 catalyst with ternary heterostructure and Z-scheme/type Ⅱ dual pathway mechanism for high photocatalytic performance

A novel Ag3PO4/g-C3N4/Zn3(PO4)2 photocatalyst with ternary heterostructure and Z-scheme/type Ⅱ dual pathway mechanism was synthesized. Scanning electron microscopy and transmission electron microscopy data showed that Ag3PO4, Zn3(PO4)2, and g-C3N4 were in close contact, leading to the formation of the ternary heterojunction. Under simulated solar light irradiation, the Ag3PO4/g-C3N4/Zn3(PO4)2 photocatalyst efficiently degraded rhodamine B (RhB) and displayed much higher photocatalytic activity than pure Ag3PO4, g-C3N4, Zn3(PO4)2, and Ag3PO4/Zn3(PO4)2 composite, exhibiting a RhB photodegradation efficiency of ∼91.2 % within 60 min. The quenching effects of different scavengers and electron spin resonance (ESR) experiments demonstrated that reactive h+ and·O2− species played major roles in the photocatalytic reaction. It was elucidated that excellent photocatalytic activity could be ascribed to the Z-scheme/type Ⅱ dual carrier transfer pathways. Therefore, the formation of a ternary heterostructure system is an efficient method for separating charge carriers and retaining their redox capabilities.

Ba3(PO4)2 Photocatalyst for Efficient Photocatalytic Application.

Barium phosphate (Ba3(PO4)2) is a class of material that has attracted significant attention thanks to its chemical stability and versatility. However, the use of Ba3(PO4)2 as a photocatalyst is scarcely reported, and its use as a photocatalyst has yet to be reported. Herein, Ba3(PO4)2 nanoflakes synthesis is optimized using sol-gel and hydrothermal methods. The as-prepared Ba3(PO4)2 powders are investigated using physicochemical characterizations, including XRD, SEM, EDX, FTIR, DRS, J-t, LSV, Mott-Schottky, and EIS. In addition, DFT calculations are performed to investigate the band structure. The oxidation capability of the photocatalysts is investigated depending on the synthesis method using rhodamine B (RhB) as a pollutant model. Both Ba3(PO4)2 samples prepared by the sol-gel and hydrothermal methods display high RhB photodegradation of 79% and 68%, respectively. The Ba3(PO4)2 obtained using the sol-gel process exhibits much higher stability under light excitation after four regeneration cycles. The photocatalytic oxidation mechanism is proposed based on the active species trapping experiments where O2 •‒ is the most reactive species. The finding shows the promising potential of Ba3(PO4)2 photocatalysts and opens the door for further investigation and application in various photocatalytic applications.