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BiVO4 and g‐C3N4 have gain attention for their potential in sustainable energy and environmental applications due to their visible light absorption properties. However, their limitations in terms of visible light absorption and electron‐hole separation have prompted efforts to enhance their energy utilization and reduce electron‐hole recombination. In our study, we investigated the fabrication of a ternary Ag/g‐C3N4/BiVO4 composite for Rhodamine B (RhB) degradation under visible light irradiation using a combination of photo‐deposition and calcination methods. Our findings demonstrate that the Ag/g‐C3N4/BiVO4 outperforms g‐C3N4, BiVO4, and g‐C3N4/BiVO4 in terms of RhB degradation rate. This improvement can be attributed to the improved light absorption and synergetic effects on charge transfer and photoelectron‐hole recombination resulting from the incorporation of Ag into the ternary system. This ternary Ag/g‐C3N4/BiVO4 composite has potential as a photocatalyst for the removal of organic pollutants due to its reasonable design and superior effectiveness. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g-C3N4) has received much interest as a visible-light-driven photocatalyst for degrading pollutants such as organic dyes and antibiotics. However, g-C3N4 bulk activity could not meet expectations due to its rapid recombination of photogenerated electron–hole pairs and low specific surface area. In our study, melamine was thermally treated one-step in the presence of NH4Cl to produce g-C3N4 nanosheets. The characterizations of surface morphology and optical properties of all g-C3N4 samples were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectrum (XPS), transmission electron microscopy (TEM), and UV–visible diffuse reflectance spectroscopy. Compared to bulk g-C3N4, g-C3N4 nanosheets demonstrated excellent photocatalytic activities, with approximately 98% RhB removal after 210 min of visible light irradiation. Furthermore, the effect of catalyst dosage, pH, and RhB concentration on the removal percentage dye of g-C3N4 nanosheets was also investigated. h+ and •O2− species were demonstrated as the key reactive species for the RhB. Besides, ECN exposed a tetracycline degradation efficiency of 80.5% under visible-light irradiation for 210 min, which is higher than BCN (60.8%). The improved photocatalytic activity of g-C3N4 nanosheets is due to the restriction of the recombination of photogenerated electrons/hole pairs, as provided by photoluminescence spectra and Nyquist plot. As a result, our research may offer an effective approach to fabricating g-C3N4 nanosheets with high photocatalytic activity and high stability for environmental decontamination. [ABSTRACT FROM AUTHOR]

This study aims to synthesize and evaluate the photocatalytic activity of bismuth terephthalate material (Bi-BDC) synthesized by solvothermal (ST) and microwave-assisted solvothermal (MW) methods. Differences in the crystal structure and crystal shape were assessed by analytical methods such as X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared (FT-IR) spectrum, X-ray photoelectron spectroscopy (XPS), N2 adsorption/desorption, Raman spectrum, and thermal gravimetric analysis (TGA). From XRD, IR, Raman, and XPS results, the fully crystallized Bi-BDC materials were achieved regardless of the preparation router. Bi-BDC-MW exhibited spherical-like morphologies, producing between stacked lamellar, while Bi-BDC-ST method exhibited a heterogeneous structure. The TGA data indicated that Bi-BDC is thermally stable up to 300 °C, suggesting the excellent thermal stability of Bi-BDC. The surface area and pore volume of Bi-BDC-MW (18 m2/g and 85 × 10−3 cm3/g) are higher than those of Bi-BDC-ST (16 m2/g and 52 × 10−3 cm3/g), which is due to its well-defined lamellar microstructure and homogeneity of the crystals. Compared to Bi-BDC-ST, Bi-BDC-MW has a higher value in the content of oxygen vacancy. Moreover, the photocatalytic efficiency of Bi-BDC-MW was significantly higher than that of Bi-BDC-ST, in which 99.44% rhodamine B (RhB) is removed after 360 min of irradiation. The improved photocatalytic efficiency of Bi-BDC-MW is ascribed to the morphology, specific surface area, and oxygen defects, which exhibited the good separation of electrons and holes, as confirmed by the photoluminescence (PL). The results should open a new approach to enhancing the photocatalytic activity of bismuth terephthalate materials. [ABSTRACT FROM AUTHOR]

BACKGROUND The development of visible light photocatalysts for CO2 reduction into methanol is a challenge, as most of the reported photocatalysts can only work in a UV light environment. Slow kinetics and poor selectivity of CO2 towards methanol are currently two significant drawbacks limiting the practical application of CO2 reduction into methanol. RESULTS: A ZnFe2O4/TiO2 heterojunction with a ratio of unity was found to lead to the highest methanol yield of 693.31 μmol (g cat)−1 under a light intensity of 100 mW cm−2. This photocatalyst also possessed the highest BET surface area of 6.5211 m2 g−1 and better morphological structure, as compared with other ratios (1:2, 2:1 w/w). Interestingly, a loading of 1 g L−1 of ZnFe2O4/TiO2 (1:1) heterojunction photocatalyst in the pre‐annealing treatment of ZnFe2O4 at 900 °C and post‐annealing treatment of ZnFe2O4/TiO2 (1:1) composite at 500 °C revealed that there was an enhancement in the interfacial interaction, and subsequently an efficient photoreduction of CO2 into methanol. CONCLUSIONS: This study demonstrates facile fabrication of p–n heterostructured phototcatalysts for reduction of CO2 with marked improvement in methanol yield under visible light irradiation. It provides a viable route for exploring the effects of composition, hydrothermal treatment, and pre‐/post‐annealing treatment of hybrid semiconductor composites used to scale up photocatalytic CO2 conversion in solar fuel‐based devices. [ABSTRACT FROM AUTHOR]

Pd/PdO‐decorated BiVO4 nanoparticles were prepared by two‐step router: (i) monoclinic scheelite BiVO4 nanoparticles were fabricated via the co‐precipitation process in the presence of urea; (ii) Pd/PdO was decorated BiVO4 surface by the combination of by precipitation method and annealing process. The as‐synthesized catalysts were characterized by X‐ray powder diffraction (XRD) analysis, Raman spectra, X‐ray photoelectron (XPS) spectra, UV‐visible diffuse reflectance (UV‐vis DRS) spectra, and photoluminescence (PL) spectroscopy. The photocatalytic performance of Pd/PdO‐decorated BiVO4 samples exhibited excellent photodegradation of rhodamine B as well as the OH• radical generation under LED light irradiation as a comparison with the bare BiVO4. This excellent outcome is due to the reduced electron/hole recombination of Pd/PdO‐decorated BiVO4 samples, which was confirmed by PL characterization. Therefore, the fabrication of semiconductors with a combination of noble metal/oxides are good candidates for enhancement of their photocatalytic performance. [ABSTRACT FROM AUTHOR]

Abstract The development of composite photocatalyst is a promising direction for improving photocatalytic performance of decomposition of organic dyes. This study aimed to fabricate two composite photocatalysts using either Fe 3 O 4 or NiFe 2 O 4 with MIL-53(Fe) as heterogeneous catalysts for the degradation of rhodamine B (RhB) under visible light irradiation by a 40 W compact fluorescent lamp. The physicochemical, the surface, the magnetic and the energy band gap of the photocatalyst were characterized by XRD, FT-IR, Raman, FE-SEM, UV–vis DRS, Brunauer–Emmett–Teller (BET), and VSM. From the photocatalytic activities test results, the NiFe 2 O 4 -doped MIL-53(Fe) sample expressed a higher photocatalytic degradation capacity of RhB than that of Fe 3 O 4 /MIL-53(Fe) sample, significantly better than that of the bare of Fe 3 O 4 , NiFe 2 O 4 , and MIL-53(Fe). [ABSTRACT FROM AUTHOR]

Bismuth MOF catalysts were successfully fabricated using the solvothermal method, which involved the use of a mixed solvent composed of DMF and ethanol in varying volume ratios. Subsequently, the catalysts underwent comprehensive characterization using diverse techniques i.e., FTIR, XRD, N2 adsorption-desorption, UV–vis diffuse, and SEM-EDX. The photocatalytic degradation of RhB was investigated using six different bismuth MOF (BiEt) catalysts. Later, parametric analysis study was performed to test the BiEt catalysts under different values of pH, Rhodamine B (RhB) dye concentrations, and different scavengers. The results showed that BiEt1 had total surface area of 16.78 m2/g and pore volume of 0.025 cm3/g with a pore size of 1.5331 nm. The photocatalytic performance of the catalysts was assessed by quantifying the removal capacity and analyzing theUV–vis absorption spectra during the degradation of RhB. The results show that BiEt 1 had the highest photodegradation efficiency toward the RhB and that it required the shortest time of 60 min to achieve 100% removal. The UV–vis absorption spectra of BiEt catalysts during the degradation of RhB showed that the characteristic absorption wavelength of RhB was observed at 576 nm. These findings suggest that the prepared BiEt was an exceptional photocatalyst for the degradation of RhB. It has great potential for environmental remediation applications. [Display omitted] • Bismuth MOF catalysts revealed exceptional photocatalytic performance, achieving 100% removal of RhB dye within 60 min. • BiEt1 exhibited highest removal capacity of RhB and possessed a total surface area of 16.78 m2/g. • DMF/ethanol solvent mixture improved the photocatalytic efficiency. • The pH significantly influenced the photocatalytic activity of Bi-BTC catalysts. • Scavengers hindered efficiency of RhB degradation. [ABSTRACT FROM AUTHOR]

The designed synthesis of an S-scheme heterojunction has possessed a great potential for improving photocatalytic wastewater treatment by demonstrating increased the photoredox capacity and improved the charge separation efficiency. Here, we introduce the fabrication of a heterojunction-based photocatalyst comprising bismuth oxychloride (BiOCl) and bismuth-based halide perovskite (BHP) nanosheets, derived from metal-organic frameworks (MOFs). Our composite photocatalyst is synthesized through a one-pot solvothermal strategy, where a halogenation process is applied to a bismuth-based metal-organic framework (CAU-17) as the precursor for bismuth sourcing. As a result, the rod-like structure of CAU-17 transforms into well-defined plate and nanosheet architectures after 4 and 8 h of solvothermal treatment, respectively. The modulation of the solvothermal reaction time facilitates the establishment of an S-scheme heterojunction, resulting in an increase in the photocatalytic degradation efficiency of rhodamine B (RhB) and sulfamethoxazole (SMX). The optimized BiOCl/BHP composite exhibits superior RhB and SMX degradation rates, achieving 99.8% degradation of RhB in 60 min and 75.1% degradation of SMX in 300 min. Also, the optimized BiOCl/BHP composite (CAU-17-st-8h sample) exhibited the highest rate constant (k = 3.48 × 10−3 min−1), nearly 6 times higher than that of the bare BHP in the photocatalytic degradation process of SMX. The enhanced photocatalytic efficiency can be endorsed to various factors: (i) the in-situ formation of two-components BiOCl/BHP photocatalyst, derived from CAU-17, effectively suppresses the aggregation of pristine BHP and BiOCl particles; (ii) the S-scheme heterostructure establishes a closely-knit interfacial connection, thereby facilitating efficient pathways for charge separation/transfer; and (iii) the BiOCl/BHP heterostructure enhances its capacity to absorb visible light. Our investigation establishes an effective strategy for constructing heterostructured photocatalysts, offering significant potential for application in photocatalytic wastewater treatment. [Display omitted] • In-situ formation of heterojunction-based photocatalyst (BiOCl/BHP) from CAU-17. • The S-scheme BiOCl/BHP heterojunction significantly boots photocatalytic efficiency. • BiOCl/BHP exhibits impressive degradation rates: 99.8% for RhB and 75.1% for SMX. • Closely-knit interfacial connection in heterojunction boots charge separation efficiency. [ABSTRACT FROM AUTHOR]

Our study explores the effect of different solvents on the synthesis of bismuth-based halide perovskite (BHP) crystals with distinct morphologies. BHP crystals were successfully synthesized using various alcohol solvents, including ethanol (EtOH), butanol (BuOH), ethylene glycol (EG), glycerol (GL), and without the use of alcohol solvents. The choice of solvent acted a crucial role in shaping the nucleation and growth of BHP crystals, as it affected key solvent characteristics, including dielectric constant, ion-coordination, and atomic chain length. The resulting BHP crystals exhibited varying geometrical and structural features, which, in turn, significantly impacted their photophysical properties and photocatalytic activity for the degradation of organic pollutants under visible light irradiation. The introduction of EtOH into the synthesis process led to larger crystallite sizes and an increased adsorption of oxygen molecules on BHP, thereby enhancing the separation of photo-excited electrons and holes. Consequently, the photodegradation efficiency of rhodamine B achieved an impressive 99.6% after 30 min of irradiation. The degradation rate of tetracycline hydrochloride over BHP photocalysts followed this order: mesoporous structure with strong agglomeration of particles (EtOH) > irregular agglomerates composed of spherical particles (BuOH) > irregular clusters of sheets (EG) > thick plates (GL) > flower-like agglomerates (without the use of an alcohol solvent). Our evaluation considered changes in morphological characteristics, surface properties, and photon absorption capacities of the BHP crystalline structures. This study provides valuable insights into the role of various alcohol solvents in tailoring the structure and improving the photocatalytic performance of BHP photocatalyst synthesized through the solvothermal route. [Display omitted] • Morphology and structure of BHP depend on the choice of alcohol solvents. • Ethanol introduction enhances BHP crystallite size and oxygen adsorption. • Photoactivity varies with BHPs morphologies and structure. • BHP–EtOH achieves remarkable 79.6% TCH degradation under white LED light. • BHP–EtOH also achieves impressive 99.6% RhB degradation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bismuth based MOFs were synthesized by the microwave-assisted solvothermal method. • Bi-TATB showed a high specific surface area. • Bi-TATB showed excellent photocatalytic activity (k = 32.1 × 10−3 min−1). • The mechanism of RhB photodegradation process over Bi-MOF was investigated. • Bi-TATB showed excellent photocatalytic O 2 evolution. In this study, we studied the effect of starting ligands such as 1,4-benzenetdicarboxylic (H 2 BDC), 1,3,5-benzenetricarboxylic (H 3 BTC), and 4,4′,4″-s-triazine-2,4,6-triyl-tribenzoic (H 3 TATB) acids on the photocatalytic activity of three bismuth-based MOFs (Bi-MOF) obtained via a microwave-assisted solvothermal process. Different shapes and sizes of ligands displayed different structure properties from the corresponding Bi-MOF. Specifically, Bi-MOF composed of Bi3+ and H 3 TATB (Bi-TATB) exhibits the largest specific surface area of 355 m2/g, highest surface-oxygen vacancy amount, a more vigorous light absorption intensity with a broader range of visible light absorption and red-shifted absorption edge than that of Bi-MOF composed of Bi3+ and H 2 BDC (Bi-BDC) and Bi-MOF composed of Bi3+ and H 3 BTC (Bi-BTC), suggesting the extension in the photocatalytic activity for Bi-TATB. The reason is attributed to the difference in their structural features. Compared with H 2 BDC and H 3 BTC ligands in Bi-BDC and Bi-BTC, H 3 TATB ligands in the structure of Bi-TATB contained more delocalized π electrons. This outcome may facilitate the ligand-to-metal charge transfer (LMCT) and decrease the electronic bandgap of the Bi-TATB, thus contributing to the enhanced photocatalytic rate. The enhanced photocatalytic activity of Bi-TATB was further confirmed by the photodegradation of rhodamine B (RhB) under LED light irradiation, which is 99.1% of RhB removal after 180 min of light irradiation. The as-synthesized Bi-TATB showed promising photocatalytic activity for the degradation of organic dye with an excellent recyclable catalytic efficiency. With the above understanding, Bi-MOF was finally used for the photocatalytic O 2 evolution from water under LED light irradiation. The Bi-TATB had a maximum photocatalytic O 2 evolution rate of 691 μmol h−1. To the best of the author's knowledge, there has been no research on both the photocatalytic degradation of organic model dye pollutants and photocatalytic O 2 evolution studies using Bi-MOFs with different organic linkers. The results should open an alternative approach of ligand selection that could increase the applicability of Bi-MOF in the field of catalysis. [ABSTRACT FROM AUTHOR]

Iron metal-framework MIL−88B(Fe) (chemical formula: Fe 3 O [C 6 H 4 (CO 2) 2 ] 3 OH.nH 2 O) has received much attention as a promising catalyst for the degradation of organic dyes. Unfortunately, some MOFs suffer from a deficiency of stability; thus, limiting their range of applications. To handle this problem, we attempted to replace Fe3+ ions with other metal ions at different ratios to improve the photocatalytic performance. Briefly, M/Fe−MOFs (M = Ni, Mg and Sn) with remarkably different properties were obtained using the microwave-assisted solvothermal method. The morphology of the synthesized bimetallic metal-organic frameworks was characterized by SEM and TEM; while their physical and chemical properties were defined by XRD, FT−IR, Raman, XPS, UV–vis DRS, and BET. The photocatalytic performance of the prepared materials was explored through the photocatalytic degradation of organic dyes (rhodamine B (RhB), crystal violet (CV), methyl orange (MO) and methylene blue (MB)) under irradiation of visible light was explored. The result showed that 10%Ni/Fe-MOF sample achieved above 96 % of RhB removal after 120 min of irradiation. The effects of pH solution, catalyst dosage and RhB concentration on RhB decomposition efficiency were carefully investigated. Furthermore, the present study has proposed a mechanism of RhB dye degradation reaction by bimetallic MOFs catalysts. Additionally, the free radical scavenging experiment has found that OH• and h+ radicals took the main responsibility for RhB decomposition. The stability and reliability of 10%Ni/Fe-MOF were also evaluated via the leaching and reusability tests. Interestingly, the photocatalyst performance experienced a negligible reduction after five consecutive usages. The results are expected to broaden the knowledge of bimetallic MOF synthesis and its applications. [Display omitted] • Bimetallic M/Fe−MOFs (M = Ni, Mg and Sn) were synthesized microwave-assisted solvothermal method • 10%Ni/Fe-MOF achieved above 96 % of rhodamine B (RhB) removal after irradiation for 120 min • A mechanism of RhB dye degradation reaction by bimetallic MOFs catalysts has been proposed • The photocatalyst performance experienced negligible reduction after five consecutive usages. [ABSTRACT FROM AUTHOR]