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Bi2O3/TiO2 photocatalysts were successfully synthesized by the solvothermal method. Characterization using X‐ray powder diffraction, scanning electron microscopy, UV‐visible diffuse reflectance spectra, X‐ray photoelectron spectroscopy, and photoluminescence spectroscopy showed excellent photodegradation of tetracycline under UV‐visible light, compared to Bi2O3 or TiO2. This was due to reduced electron‐hole recombination in the Bi2O3/TiO2 composite, as confirmed by photoluminescence characterization. The fabrication of semiconductor composites holds great promise for enhancing the photocatalytic performance, and Bi2O3/TiO2 is a prime example with exciting prospects for practical applications in photocatalysis. [ABSTRACT FROM AUTHOR]

Pollution of waste and natural waters by antibiotics is a major health issue that induces the development of resistant pathogens. Pollutant may be removed by photocatalysis, yet classical photocatalysis is limited by the short carrier lifetime. Here, we review multicomponent photocatalysts for the synergic degradation of antibiotics. Components include metallic nanoparticles, semiconductors and adsorbents. The synergy of these components provide photocatalysts with advantages such as extended visible-light range with bandgap energy lower than 2.8 eV, improved charge transfer properties, enhanced adsorption capacity and more active reaction sites. The removal of the antibiotics, based on the decrease of the initial concentration, reaches 80–100%, but mineralization is rarely measured in reports. Proposed mechanisms for the photocatalytic degradation of antibiotics over single and multicomponent photocatalysts are discussed. [ABSTRACT FROM AUTHOR]

In this study, the g-C3N4 with simultaneous isotype heterojunction and porous structure showed superior photocatalytic decomposition of tetracycline hydrochloride (TCH) under white LED light irradiation fabricated via a thermal polycondensation method using melamine and thiourea as precursors and NH4Cl as soft-template. X-ray diffraction and transmission electron microscopy demonstrated the successful fabrication of the heterojunction between two different phases of g-C3N4 metal-free semiconductor. Besides, the increase in surface area as well as the porosity of g-C3N4 isotype heterojunction compared with CN-M (the g-C3N4 was synthesized using melamine as precursor) or CN-T (the g-C3N4 was synthesized using thiourea as precursor) was confirmed through nitrogen adsorption–desorption isotherms. The improved photocatalytic degradation of TCH over CN-MT (the g-C3N4 was synthesized using melamine and thiourea as precursors and NH4Cl as soft-template) compared to CN-M and CN-T could be assigned to the visible light absorption expansion, the increase in surface area as well as the porosity and reduction of photo-generated electron–hole pair recombination. Specifically, the CN-MT-1:1 isotype heterojunction revealed the highest photocatalytic activity for TCH degradation (81.55%) within 180 min. Furthermore, this catalyst can be recycled four times, which demonstrates the potential of CN-MT as a visible light-sensitive catalyst for organic pollutant removal. [ABSTRACT FROM AUTHOR]

The effects of the substitution of V5+ with Ni2+ at the corresponding sites in BiVO4 on the crystal structures, optical properties, and photocatalytic efficiency of BiVO4 was investigated. Ni2+ cations doped at the V5+ sites in BiVO4 was confirmed by X-ray diffraction, Raman, X-ray photoelectron spectroscopy, ultraviolet–visible diffuse reflectance spectra, and photoluminescence spectra. Ni-doped BiVO4 exhibited excellent degradation of crystal violet (CV) compared with the bare BiVO4. For optimal Ni2+ doping of 5%, the degradation rate of CV, which reached about 95% within 180 min of LED light irradiation, was obtained. Ni doping can introduce advantageous defect states that significantly increase the separation and diffusion efficiency of the photo-induced charge carriers, thereby boosting the photocatalytic activity of crystal structures. [ABSTRACT FROM AUTHOR]

Sigle phase scheelite-monoclinic BiVO4 materials with different morphologies were successfully fabricated via a facile hydrothermal process by controlling pH of the precursor. The photocatalytic properties of the as-prepared materials were assessed via the photodecomposition of crystal violet (CV) solution under a 60 W LED (Cree-L6) visible light irradiation. The Langmuir-Hinshelwood model was utilized to present kinetic behavior. The obtained BiVO4 exhibited a monoclinic crystalline structure and narrow bandgap energy (Eg = 2.3–2.6 eV), which were confirmed by the X-ray diffraction (XRD), Raman and UV-vis diffuse reflectance spectra (UV-vis DRS) results. From the scanning electron microscopy (SEM) results, BiVO4 morphologies could be facilely controlled by turning the pH value of the precursor. When pH = 0.3, the BiVO4 products showed spherical morphologies with particle sizes in the range of 1–5 µm. Rod- and spherical like-BiVO4 products were obtained when the pH of the precursor was adjusted to 3. Moreover, BiVO4 with nanoparticles could be prepared under the pH of 5–7, whereas leaf-like morphologies could be achieved when pH = 9. The photocatalytic test showed that the adsorption equilibrium constant depended on the morphologies of the BiVO4 products and the reaction rate constant was reached the highest level at pH = 3. This outcome indicated that the enhanced performance of BiVO4 significantly depended on the morphologies of the BiVO4 products and the effective suppression of photo-excited electrons and holes. [ABSTRACT FROM AUTHOR]

In this study, BiVO 4 was successfully synthesized via the solvothermal process using a solvent mixture of ethylene glycol and water under different synthesis conditions of temperature and pH. Physicochemical properties such as crystal phase, morphology, and optical absorption of the as-synthesized BiVO 4 samples were characterized by X-ray diffraction (XRD), Raman spectra, field emission scanning electron microscopy (FE-SEM), and ultraviolet–visible diffraction reflection spectroscopy (UV–vis DRS). The XRD analysis showed that different synthesis conditions of temperature and pH significantly affected the growth of monoclinic BiVO 4 crystals oriented along (0 4 0) facets. Form SEM results, the synthesis conditions, including pH and temperature, have a great effect on the morphology of monoclinic structured BiVO 4. As the pH value increases in the range of 0–9 and temperature increases from 80 °C to 180 °C, the morphology of BiVO 4 changed from peanut-, rod-, and leaf-like shapes. The photocatalytic activities of as-synthesized BiVO 4 photocatalysts were evaluated by the photodegradation of methylene blue (MB) dye under irradiation of white LED light. We have found that by using appropriate synthesis conditions (the synthesis temperature of 140 °C and the synthesis pH of 7) the BiVO 4 exhibited high photocatalytic efficiency for MB degradation (about 82.30% after 180 min of irradiation). This result is due to the development of the BiVO 4 crystals oriented along (0 4 0) facets with an increase in the intensity ratio of I (0 4 0) /I (1 2 1). The growth of BiVO 4 crystals oriented along (0 4 0) facets may be beneficial to enhance the photocatalytic activity of monoclinic scheelite BiVO 4. [ABSTRACT FROM AUTHOR]

We synthesized BiVO 4 photocatalysts using a facile solvothermal router and three different mixed solvents, 2-methoxyethanol (MEOH), 1,2-ethanediol (EDOH), and 1,2,3-propanetriol (PTOH) with water, which we then characterized by XRD, XPS, FE-SEM, and UV–vis DRS. The XRD results show that we obtained single-phase monoclinic scheelite (m-s BiVO 4) in the EDOH/water and PTOH/water systems and monoclinic/tetragonal heterostructure BiVO 4 (m-t BiVO 4) in the MEOH and water mixture. m-t BiVO 4 with a monoclinic/tetragonal heterostructure prevents the recombination of photoexcited electron-hole pairs. As such, of the three samples, the m-t BiVO 4 material showed the highest activity in the photodecomposition of rhodamine B. Unlabelled Image • A solvothermal router was use to control the morphology and phase structure of BiVO 4. • m-s BiVO 4 was obtained in the ethane-1,2-diol/water or propan-1,2,3-triol/water. • m-t heterostructure BiVO 4 was obtained in 2-methoxyethanol/water. • Heterostructure was more effective than m-s phases in RhB degradation under visible-light. • Heterojunctions could hinder the recombination of photoexcited electron-hole pairs. [ABSTRACT FROM AUTHOR]

In this study, we investigated sulfate-modified BiVO4 with the high photocatalytic activity synthesized by a sol-gel method in the presence of thiourea, followed by the annealing process at different temperatures. Its structure was characterized by thermal gravimetric analysis (TGA), powder X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). The BiVO4 synthesized in the presence of thiourea and calcined at 600 °C (T-BVO-600) exhibited the highest photocatalytic degradation efficiency of methylene blue (MB) in water; 98.53% MB removal was achieved within 240 min. The reaction mechanisms that affect MB photocatalytic degradation on the T-BVO-600 were investigated via an indirect chemical probe method, using chemical agents to capture the active species produced during the early stages of photocatalysis, including 1,4-benzoquinone (scavenger for O2−), ethylenediaminetetraacetic acid disodium salt (scavenger for h+), and tert-butanol (scavenger for HO•). The results show that holes (h+) and hydroxyl radicals (HO•) are the dominant species of MB decomposition. Photoluminescence (PL) measurement results of terephthalic acid solutions in the presence of BiVO4 samples and BiVO4 powders confirm the involvement of hydroxyl radicals and the separation efficiency of electron-hole pairs in MB photocatalytic degradation. Besides, the T-BVO-600 exhibits good recyclability for MB removal, achieving a removal rate of above 83% after five cycles. The T-BVO-600 has the features of high efficiency and good recyclability for MB photocatalytic degradation. These results provide new insight into the purpose of improving the photocatalytic activity of BiVO4 catalyst. [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]

Ag x -Zn 100−x -BTC/GO composites (BTC: benzene-1,3,5-tricarboxylic, GO: graphene oxide) with different Ag/Zn molar ratios were synthesized using microwave-assisted hydrothermal treatment. The Ag x -Zn 100−x -BTC/GO exhibited excellent photocatalytic performance in the reactive yellow 145 dye (RY-145) degradation under irradiation of visible light with nearly 100% of RY-145 removal after 35 min, as compared to Zn-BTC/GO and Ag-BTC/GO. Reactive oxygen species scavenging assays have shown that the holes (h+) and superoxide radical anion (O 2 −•) play a primary role in RY-145 degradation. Based on the band structure of materials, the Z-scheme photocatalytic mechanism was suggested. The effect of catalyst dosage, pH and dye concentration on the efficiency of photocatalytic activity of bimetallic Ag 50 -Zn 50 -BTC/GO was also investigated. The improvement in photocatalytic activity of bimetallic Ag 50 -Zn 50 -BTC/GO could be given by the synergism of (i) absorption of visible light confirmed by UV-Vis diffuse reflectance spectra; (ii) the increased lifetime as evidenced by photoluminescence spectra and transient photocurrent response; (iii) the increased oxygen vacancy defects as confirmed by X-ray photoelectron spectroscopy results. The degradation pathway of RY-145 dye was also predicted based on liquid chromatography-mass spectrometer analysis. The removed chemical oxygen demand, biological oxygen demand, total organic carbon outcomes indicated the high mineralization ability for RY-145 degradation over Ag 50 -Zn 50 -BTC/GO. [Display omitted] • Microwave-assisted synthesis of Ag x -Zn 100−x -BTC/GO composites was investigated. • The Ag 50 -Zn 50 -BTC/GO could degrade nearly 100% RY-145 within 35 min • The Ag 50 -Zn 50 -BTC/GO exhibits high mineralization ability for RY-145 degradation. • The degradation pathways of reactive yellow 145 were deduced from LC-MS analysis. • This improvement is due to bimetallic Ag/Zn in the SBU network. [ABSTRACT FROM AUTHOR]

Photocatalytic technology represents a cutting-edge approach for addressing water pollution. The performance of photocatalysts can be improved by constructing of heterojunctions that facilitate the charges transfer between the two components. Herein, we produced a three-component g–C 3 N 4 /g–C 3 N 4 isotype heterojunction/bismuth-based halide perovskites (g–C 3 N 4 –ISO/BHP) composite using a solvothermal method to grow bismuth-based halide perovskite (BHP) onto the surface of g–C 3 N 4 /g–C 3 N 4 isotype heterojunction (g–C 3 N 4 –ISO) layers. Several methods were used to investigate crystalline structure, morphology, chemical composition/states, optical characteristics, and charge-carrier dynamics of the three-component composite. The g–C 3 N 4 –ISO/BHP composite exhibited superior photocatalytic activity under white LED light with a degradation percentage of 73.2%, which is higher than the mixed-phase g–C 3 N 4 –ISO (61.4%) and the bare BHP (62.5%). The control of component content improved the transmission of charges between the composite components. The S-scheme charge transfer mechanism was verified to function on the g–C 3 N 4 –ISO/BHP composite as a result of its high compatibility and adequate band structure, resulting in robust redox ability, effective charge carrier separation and extended lifetime. Our study presents a practical approach for constructing three-component composites for efficient photocatalytic water treatment. [Display omitted] • A g–C 3 N 4 /g–C 3 N 4 /BHP composite enhances photocatalytic degradation of TCH. • The g–C 3 N 4 /g–C 3 N 4 /BHP displays 73.2% TCH degradation rate under white LED light. • The S-scheme charge transfer route enbles effective charge carrier separation. • The S-scheme charge transfer route also demonstrates robust redox ability. [ABSTRACT FROM AUTHOR]

The potential of green nanomaterials for environmental and agricultural fields is emerging due to their biocompatible, eco-friendly, and cost-effective performance. We report the use of Canna indica flowers extract as new capping and stabilizing source to bio-fabricate ZnO nanoparticles (ZnO NPs for dyes removal, seed germination. ZnO NPs was biosynthesized by ultrasound-assisted alkaline-free route to reach the critical green strategy. The physicochemical findings of ZnO revealed small crystallite size (27.82 nm), sufficient band-gap energy (3.08 eV), and diverse functional groups. Minimum‑run resolution IV approach found the most pivotal factors influencing on removal of Coomassie Brilliant Blue G-250. Uptake studies pointed out that pseudo second-order, and Langmuir were the best fitted models. Dye molecules behaved monolayer adsorption on ZnO surface layers, and controlled by chemisorption. Natural solar light was used as effective source for photocatalytic degradation of methylene blue (94.23% of removal and 31.09 mg/g of uptake capacity). Compared with H 2 O and ZnSO 4 , ZnO NPs positively affected the growth of shoot and root lengths (10.2–27.8%) of bean seedlings in most cases. ZnO acts an agrochemical for boosting weight gain, and germination ratio. This study may be promising for developing the recyclable, multifunctional ZnO nanoparticles for environmental and agricultural applications. [Display omitted] • ZnO nanoparticles were biosynthesized from Canna indica L. flowers. • Minimum–run resolution IV was used to screen and optimize the adsorption parameters. • Photodegradation of methylene blue was conducted under solar light illumination. • ZnO nanoparticles boosted shoot and root lengths of green and red bean seedlings. • Good recyclability and high removal efficiency were obtained. [ABSTRACT FROM AUTHOR]