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BACKGROUND: Bismuth tetraoxide (Bi2O4) has attracted increasing interest as a novel visible‐light‐driven photocatalyst. It suffers from some drawbacks, such as quick recombination of photogenerated electrons and holes, small specific surface area and few active sites due to submicron rod structure. RESULTS: A novel and efficient binary heterojunction photocatalyst, in which zero‐dimensional (0D) SnO2 nanoparticles was anchored on the surface of one‐dimensional (1D) Bi2O4 micrometer rods, was successfully synthesized. The as‐prepared samples were characterized by X‐ray diffraction (XRD), scanning electron microscopy, transmission electron microscope, Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy. The photocatalytic activity of the synthesized photocatalysts was evaluated by photodegradation of tetracycline (TC) under visible‐light irradiation. The prepared 30‐SB composite (30 wt% SnO2/Bi2O4) exhibits the highest photocatalytic activity toward TC degradation. The removal efficiency of TC was up to 84.3% within 120 min. The rate constant k for the reaction of 30‐SB composite is 0.029017 min−1, which is 13.4 and 1.8 times as high as that of SnO2 and Bi2O4, respectively. CONCLUSION: The significantly boosted photocatalytic activity is attributed to the formation of Z‐scheme heterojunctions between SnO2 and Bi2O4. Z‐scheme charge transfer promoted the effective separation of photogenerated carriers and ensured that the holes with higher oxidative activity and electrons with stronger reducibility participate in the production of •OH and •O2− as well as direct degradation of TC. This work will provide a new modification strategy for the potentially excellent photocatalyst Bi2O4. © 2022 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

A novel ternary heterojunction composite photocatalyst g-C3N4/TiO2/NiWO4 was fabricated using a simple hydrothermal method. The synthesized samples were characterized using X-ray diffraction (XRD), scanning electronic microscopy (SEM), energy-dispersive spectrum (EDS), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible (UV–Vis) absorption spectra, photoluminescence (PL) spectra, transient photocurrent responses, and electrochemical impedance spectroscopies (EIS). The results indicated that the composite of g-C3N4/TiO2/NiWO4 had been successfully synthesized. By constructing a ternary heterojunction, the electron migration rate and light absorption of the material are further improved; the photogenerated electron–hole recombination is inhibited. The ternary composite photocatalyst shows the highest photocatalytic activity for the degradation of rhodamine B (RhB) than that of g-C3N4, TiO2, NiWO4, and g-C3N4/TiO2 photocatalyst. The degradation efficiency of RhB using g-C3N4/TiO2/NiWO4 can reach 99% after visible-light irradiation for 40 min. Finally, the migration mechanism of charge carriers in the ternary system has been schematically illustrated by the active species capture experiment. Our research can pave the way for the fabrication of ternary heterojunction composite photocatalyst with high photocatalytic activity for the environmental contaminants treatment. [ABSTRACT FROM AUTHOR]

BACKGROUND: A Z‐scheme structured photocatalyst is a highly efficient photocatalyst for hydrogen evolution and degradation of pollutants. RESULTS: An indirect Z‐scheme heterojunction g‐C3N4/CQDs/InVO4 with carbon quantum dots (CQDs) as electron mediator was constructed and was successfully synthesized using a facile hydrothermal method. The photocatalytic activity of the as‐prepared composite was evaluated in terms of hydrogen generation and degradation of rhodamine B (RhB) dye. The as‐prepared sample CV20/CQDs2 (g‐C3N4/2 wt% CQDs/20 wt% InVO4) exhibits the best photocatalytic activity towards hydrogen production and RhB degradation. Within 90 min, 99.6% of RhB is removed, and the degradation rate constant of RhB over CV20/CQDs2 is 0.06491 min−1, which is 43.9, 6.64 and 3.3 times as high as that of InVO4, g‐C3N4 and binary composite g‐C3N4/InVO4. CV20/CQDs2 exhibits H2 evolution rate of 2.169 mmol g−1 h−1, which is 26.07, 2.65 and 1.6 times as high as that of InVO4, g‐C3N4 and g‐C3N4/InVO4. CONCLUSIONS: The enhanced photocatalytic activity is attributed to two aspects. First, CQDs, as electron mediator, promote the effective separation of photogenerated electrons and holes through Z‐scheme charge transfer pathway, preserving the high redox ability of electrons and holes. Second, g‐C3N4/CQDs/InVO4 shows strong optical absorption in the full visible‐light region. © 2021 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

• 0D/3D CeO 2 /ZnIn 2 S 4 Z-Scheme heterojunction was prepared by a facile method. • The heterostructure exhibited outstanding photocatalytic activity for TC degradation. • The intermediates generated during the reaction process were analyzed by LC/MS. • The possible photocatalytic degradation path of TC was proposed. Reasonable designing heterojunction photocatalysts is an effective way to improve the photocatalytic activity of semiconductor. Herein, the efficient binary heterojunction photocatalyst formed between zero-dimensional (0D) CeO 2 nanoparticles and three-dimensional (3D) floriated shaped ZnIn 2 S 4 microspheres was synthesized by a simple solvothermal method. A series of analytical methods were used to characterize the optical properties and morphology of CeO 2 /ZnIn 2 S 4 composite photocatalysts. Photodegradation experimental results showed that CeO 2 /ZnIn 2 S 4 composites displayed strong photocatalytic activity for the degradation of tetracycline (TC) with heavy concentrations (30 mg/L). The as-obtained optimum 10 wt% CeO 2 /ZnIn 2 S 4 sample displays high degradation efficiency of 91% within 120 min, which is about 12.9 and 3.03 times higher than that of pure CeO 2 and ZnIn 2 S 4 , respectively. The enhanced photocatalytic activity is ascribed to the formation of Z-scheme heterojunction between CeO 2 and ZnIn 2 S 4 , which contributes to the increased surface area, enhanced redox ability and high separation efficiency of photogenerated charge carriers. The degradation pathways and intermediate products of TC over CeO 2 /ZnIn 2 S 4 composite were analyzed by liquid chromatography-mass spectrometry (LC/MS) measurement. This study provides a new approach to prepare of efficient 0D/3D-based Z-scheme heterojunction photocatalysts. [ABSTRACT FROM AUTHOR]

The aim of this article is to provide an effective catalyst for using photocatalytic technology to solve the antibiotic pollution. For this purpose, Bi 2 S 3 was loaded on the surface of MIL-88 (A) to prepare rod-shaped composite photocatalyst via a combination of low-temperature hydrothermal and low-temperature water bath methods. The prepared composite photocatalysts were characterized by using SEM, EDS, XRD, FT-IR, UV–vis and XPS. Tetracycline hydrochloride (TC) degradation under visible light was used to gauge the photocatalytic activity of the composite as it was created. The results show that the degradation efficiency of the optimum sample Bi 2 S 3 /MIL-88 (A)-0.2 to TC within 120 min in a 10 mg/L TC solution is as high as 93%, which is 5.74 and 4.39 times as high as that of pure MIL-88 (A) and Bi 2 S 3 , respectively. The increased photocatalytic activity is ascribed to the type II heterojunctions that develop between Bi 2 S 3 and MIL-88 (A), which contribute to increase the composite's specific surface area and separation efficiency of photogenerated carriers. Additionally, the possible photocatalytic mechanism of the composite photocatalyst is explored in detail by active species capture experiments, transient photovoltage electrochemical impedance spectroscopy and photoluminescence measurements. This research provides a new way to prepare MIL-88 (A)-based type II heterojunction photocatalysts. [Display omitted] • A novel photocatalyst B 2 S 3 /MIL-88(A) (BM) was prepared by an energy-saving method. • The prepared BM-0.2 has markedly enhanced degradation ability to TC. • The photocatalytic mechanism of BM-0.2 is studied in detail. [ABSTRACT FROM AUTHOR]

Hierarchical hollow heterostructures with ultrathin two-dimensional (2D) nanosheet subunits have various intrinsic advantages in photocatalytic aspects such as increasing light collection, accelerating electron hole separation and migration, and promoting surface redox reactions. Herein, we demonstrated the rational design and construction of hierarchical hollow core-shell g-C 3 N 4 @ZnIn 2 S 4 heterostructures with coating the ZnIn 2 S 4 nanosheets on the hollow g-C 3 N 4 spheres by a low temperature solvothermal route. The hollow g-C 3 N 4 @ZnIn 2 S 4 spherical nanoflower realized the improvement of photocatalytic activity by multiple scattering and reflection of light in the spherical cavity. Furthermore, the photo-generated charge carriers can be effectively separated by constructing layered heterojunctions. The optimized g-C 3 N 4 @ZnIn 2 S 4 exhibited the outstanding photocatalytic performance (nearly 84% degradation of tetracycline within 60 min visible light irradiation) as well as excellent cyclical stability. In addition, the total organic carbon removal (TOC) rate of the optimal g-C 3 N 4 @ZnIn 2 S 4 composite photocatalyst can be reached up to 64%. Meanwhile, the possible degradation intermediates and degradation paths were analyzed by liquid chromatograph-mass spectrometer (LC-MS) test results. This work provides a feasible design idea of constructing the core-shell hierarchical hollow heterostructure photocatalyst with high photocatalytic performance. • Unique layered hollow heterojunction improve the utilization rate of visible light. • Hollow core-shell g-C 3 N 4 @ZnIn 2 S 4 provide abundant reaction sites. • g-C 3 N 4 @ZnIn 2 S 4 exhibits the outstanding photocatalytic degradation activity of TC. [ABSTRACT FROM AUTHOR]