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A novel SrWO 4 /g-C 3 N 4 heterojunction was formed by simple one-pot calcination process and the wide-band gap semiconductor SrWO 4 was in-situ formed on g-C 3 N 4. The prepared photocatalysts were characterized by X-ray diffraction, Scanning Electron Microscopy, Transmission Electron Microscope, Fourier transform infrared spectroscopy, UV–vis diffuse reflectance spectra and Photoluminescence Spectroscopy to investigate the structures, morphology and optical properties of the synthesized materials. The results revealed that SrWO 4 nanoparticles were uniformly distributed on the surface or inside of g-C 3 N 4 to form a compact heterostructure and improved the photocatalytic performance of the material. The binary heterojunction showed better photodegradation efficiency of tetracycline (TC) than pure g-C 3 N 4 and SrWO 4. 88.57% of TC could be degraded by 8% SrWO 4 /g-C 3 N 4 in 2 h under the best experimental conditions. The pH value had little influence on the degradation effect, and the TC degradation rate under strong acid reached 93.94%. In addition, 77.42% TC was still degraded after the fourth cycle. It was concluded that the enhancement of photocatalytic activity due to the inhibition of electrical charge recombination and the improved light absorption capacity. Finally, free radicals capture experiment proved that·O 2 - was the most important active factor of TC degradation, and the possible photocatalytic mechanism was proposed. Schematic diagram of photo-generated electron transfer mechanism of TC degradation by SW/CN under the visible light. [Display omitted] • A novel in-situ visible light-driven SrWO 4 /g-C 3 N 4 nanocomposite photocatalyst prepared by one-pot calcination. • The tetracycline degradation performance of binary heterojunction is stronger than that of pure g-C 3 N 4 by loading SrWO 4. • A special e- one-way transfer mechanism and ·O 2 - account for the enhanced photocatalytic activity. [ABSTRACT FROM AUTHOR]

A novel and efficient ternary composite AgCl/Bi 12 O 15 Cl 6 /g-C 3 N 4 photocatalyst was prepared by co-precipitation method. The physical structure and photochemical properties of the photocatalyst were analyzed by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Ultraviolet diffuse reflectance spectroscopy (UV-DRS), Fluorescence spectroscopy (PL). The performance of the prepared photocatalysts was evaluated by performing degradation experiments of tetracycline (TC) under different conditions (doping ratio, dosage, initial concentration and initial pH of solution). Furthermore, the stability of composite was confirmed by cycling experiment. Finally, the mechanism of ternary composite AgCl/Bi 12 O 15 Cl 6 /g-C 3 N 4 photocatalyst for decomposition of TC in visible light was investigated by free radical capture experiment. The photoluminescence spectra showed that the peak intensity of the AgCl/Bi 12 O 15 Cl 6 /g-C 3 N 4 composite was significantly reduced compared to other materials, indicating that the photogenerated electron-hole pairs were effectively separated, which contributed to its photocatalytic activity. The composite showed higher TC degradation activity compared to g-C 3 N 4 , Bi 12 O 15 C l6 /g-C 3 N 4 and AgCl/g-C 3 N 4 , with optimum degradation rate constants of 8.2, 2.2 and 1.6 times that of g-C 3 N 4 , Bi 12 O 15 C l6 /g-C 3 N 4 and AgCl/g-C 3 N 4 , respectively. Furthermore, based on the free radical capture experiment, it was confirmed that the active species playing a major role in the reaction process were·O 2 -, followed by h+ and·OH. A double electron transfer mechanism was inferred to be formed in the AgCl/Bi 12 O 15 Cl 6 /g-C 3 N 4 composite and a possible pathway for the degradation of TC was postulated. This work provides a new approach for the effective use of solar energy, as well as a new solution strategy for the degradation of TC in wastewater. [Display omitted] The proposed photocatalytic mechanism for photocatalytic degradation of TC on AgCl/ Bi 12 O 15 Cl 6 /g-C 3 N 4. • The AgCl/Bi 12 O 15 Cl 6 /g-C 3 N 4 exhibited excellent photodegradation of tetracycline (TC) compared to the monomer. • A possible electron transfer mechanism was proposed. • The two-electron transfer mechanism promoted the separation of photogenerated electron-hole pairs in complexes. • Superoxide radical (·O 2 -) was the main reactants in photodegradation, followed by h+ and·OH. [ABSTRACT FROM AUTHOR]

BiVO 4 /g-C 3 N 4 heterojunction was successfully prepared by wet impregnation-calcination method, and as a photoactive material, a new photocatalytic system was formed by cooperating with H 2 O 2. With the illumination of visible light, the degradation efficiency of Malachite Green (MG) could reach 98.3% in 60 min. A variety of conventional characterization techniques, which include XRD, TEM, FT-IR, DRS, PL and so on, have been used to identify micromorphology, crystal structure, physical and chemical properties, and optical properties of BiVO 4 /g-C 3 N 4 heterojunction. Different factors of photocatalytic efficiency such as the amount of BiVO 4 loading on g-C 3 N 4 , catalysis doses, the dosing of H 2 O 2 , initial concentration and pH of MG solution were explored. Free radical trapping experiments and energy band analysis results indicate that a Z-type electron transfer mechanism is formed in the system, and H 2 O 2 played a significant role on the process of degradation. [Display omitted] • BiVO 4 /g-C 3 N 4 photocatalysts with excellent photocatalytic ability was fabricated. • Extended visible-light absorption and efficient charge separation due to synergistic effects of BiVO 4 /g-C 3 N 4 with H 2 O 2. • A novel Z-type electron transfer mechanism is formed in the system. [ABSTRACT FROM AUTHOR]

The possible photocatalytic mechanism schematic of the binary type-I CdIn 2 S 4 /g-C 3 N 4 heterojunctions and H 2 O 2 for photodegrading RB19 under visible light irradiation. A visible-light-driven photocatalyst CdIn 2 S 4 /g-C 3 N 4 was firstly synthesized via a facile and green wet-impregnation method. The crystal phases, particle morphologies, chemical structures and optical properties of the prepared pure g-C 3 N 4 , bare CdIn 2 S 4 and binary CdIn 2 S 4 /g-C 3 N 4 heterojunctions were measured in detail by various standard characterization techniques, such as XRD, SEM, TEM, FT-IR, DRS, and PL. And then, a novel and high-efficiency visible-light-driven photocatalytic system comprised of binary CdIn 2 S 4 /g-C 3 N 4 heterojunctions and H 2 O 2 has been successfully constructed and exhibited superior photocatalytic degradation of Reactive Blue 19 (RB19). The following results can be obtained by photochemical characterizations and photocatalysis experiments: Compared with the pristine g-C 3 N 4 , the addition of CdIn 2 S 4 to form a type-I CdIn 2 S 4 /g-C 3 N 4 heterojunction effectively increases the visible light absorption range and reduces the recombination rate of photogenerated electron-hole pairs. After 100 min visible light irradiation, the photocatalytic degradation rate of RB19 by CdIn 2 S 4 /g-C 3 N 4 was approximately 8.30 times and 2.68 times higher than that of monomer g-C 3 N 4 and CdIn 2 S 4 , respectively. After 60 min visible light irradiation, the photodegradation efficiency of the novel photocatalytic system (CdIn 2 S 4 /g-C 3 N 4 and H 2 O 2) is 1.99 times higher than that of CdIn 2 S 4 /g-C 3 N 4 for RB19. Furthermore, the photocatalytic mechanism of the novel visible-light-driven photocatalytic system was proposed and elaborated. These findings emphasize the main role of g-C 3 N 4 in the degradation of organic dyes and provide a reasonable and effective method for rational design of a high-efficiency and low-cost visible light-driven photocatalytic system. [ABSTRACT FROM AUTHOR]

The construction of new electron transfer channels is essential to improve the photocatalyst activity. Herein, a novel Ag 2 MoO 4 /SrWO 4 /g-C 3 N 4 photocatalyst with dual electron transfer channels was constructed by one-step precipitation method. The obtained photocatalysts were characterized using XRD, SEM, FT-IR, TEM, Uv-vis and PL. Under visible light, the photocatalyst was evaluated for its ability to degrade tetracycline (TC). The characterization results presented that the olive sphere-like SrWO 4 and the nanosphere-like Ag 2 MoO 4 were uniformly dispersed on the surface and pores of g-C 3 N 4 , forming a heterostructure and thereby heterojunctions, which promoted the internal electron transfer. The degradation experiments showed that the Ag 2 MoO 4 /SrWO 4 /g-C 3 N 4 improved degradation efficiency of TC under visible light relative to monomeric and binary materials. In addition, the 20AMO/8SW/CN maintained 92.19 % degradation of TC after four cycles of experiments, showing excellent reusability. During the photocatalytic process, ·O 2 -, h+, and ·OH promoted the degradation of TC. Combining with the energy band structure analysis, it was found that a novel dual electron transfer channel had been constructed among Ag 2 MoO 4 , SrWO 4 and g-C 3 N 4 , which markedly enhanced photocatalytic efficiency. The work provides a potential approach for developing efficient and stable photocatalysts. [Display omitted] • A novel visible light responsive Ag 2 MoO 4 /SrWO 4 /g-C 3 N 4 photocatalysts were fabricated by one-step precipitation method. • The introduction of SrWO 4 and Ag 2 MoO 4 optimized the separation rate of photogenerated electron hole pairs in g-C 3 N 4. • Ag 2 MoO 4 /SrWO 4 /g-C 3 N 4 presented excellent photocatalysis and photochemical stability towards degradation of tetracycline. • An efficient dual electron transfer channels was proposed based on Ag 2 MoO 4 /SrWO 4 /g-C 3 N 4 photocatalysts. [ABSTRACT FROM AUTHOR]

Photo-catalytic technology is an environmentally friendly and sustainable method for producing hydrogen peroxide (H 2 O 2) and has got increasing attention. In the work, we prepared K+-doped g-C 3 N 4 (KCN) by thermal copolymerization, and combined it with WO 3 nanoparticles by a facile deposition method to obtain the final photocatalytic composite KCN/WO 3. XRD, FT-IR, XPS, TEM, SEM, UV-Vis and EIS were used to characterize the obtained samples. The results of EIS, UV-Vis and XPS valence band spectrum indicated the K+ doping effectively promoted charge separation of g-C 3 N 4 and the valence band position of the KCN/WO 3 composite obviously shifted higher potential, which greatly enhanced photocatalytic production of H 2 O 2 and made the composite can produce H 2 O 2 at the level of mmol/L without bubbling O 2. The KCN10/WO 3 (10%) composite showed the maximum photocatalytic activity. The decomposition behavior of H 2 O 2 and recycled stability of KCN10/WO 3 (10%) were also investigated. Furthermore, a plausible mechanism of photocatalytic production of H 2 O 2 for KCN10/WO 3 (10%) was also proposed based on reactive radicals trapped experiment and quantitatively determined experiment of superoxide radicals (O 2 -) and hydroxyl radicals (OH). [Display omitted] [ABSTRACT FROM AUTHOR]

A bifunctional composite of activated carbon/carbon nitride (AC/g-C 3 N 4) with the excellent adsorption-photocatalytic performance was prepared by a facile thermal polycondensation method. The as-prepared composites were characterized by XRD、 FT-IR, XPS, Nitrogen adsorption-desorption, TEM, UV–vis DRS and EIS. It was found that the stacking g-C 3 N 4 was fragmented by AC in the process of synthesis, leading to the increased surface area and reactive sites, and facilitating the transfer of photogenerated electron-hole pairs. The adsorption kinetics and isotherms were carried out to investigate the adsorption behavior of the composites, which indicated that the adsorption behavior fitted with the pseudo-second-order model and the Freundlich adsorption model, respectively. The AC(5%)/g-C 3 N 4 composite possessed the best remove efficiency of Rhodamine B (RhB) in the adsorption-photocatalytic process, and the adsorption capacity and the photocatalytic reaction rate were 4.3 and 4.1 times higher than that of the pure g-C 3 N 4 , respectively. Additionally, the removal efficiency of cycle experiments had decreased from 97% to 82% after 3 cycles, and then to 79% after 5 cycles, indicating the excellent stability of the photocatalyst. The mechanism of the adsorption-photocatalytic degradation of RhB for the AC(5%)/g-C 3 N 4 was also proposed. Specifically, AC with excellent adsorption performance could enrich the contaminant around the composite, and then the fragmented g-C 3 N 4 captured RhB molecule rapidly and degraded it easily, improving the remove efficiency of the RhB degradation. [ABSTRACT FROM AUTHOR]