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A novel visible-light-driven InVO4/Bi2S3/g-C3N4 (VBSCN) nanocomposite photocatalyst was successfully synthesized by a wet-impregnation method. The phase, morphology, chemical composition, microstructure, and optical properties of the prepared pure g-C3N4 and ternary InVO4/Bi2S3/g-C3N4 heterojunctions were measured in detail by various characterization techniques, including powder XRD, FT-IR, TEM, SEM, BET, UV–Vis DRS, PL, the photocurrent response, and EIS analyses. The fabricated nanocomposites Bi2S3/g-C3N4 with the InVO4 doping mass ratio of 5% exhibited superior photocatalytic degradation of Reactive blue 19 dye under visible light irradiation. Furthermore, O2− was identified as the main active species by free radical trapping. This efficient catalysis was benefited from the doping of InVO4, which reduced the wide intrinsic band gap and improved the absorption and utilization ability of visible light. Meanwhile, a dual Z-scheme heterostructure interface was constructed to realize the rapid separation of photogenerated electron–hole pairs. This investigation may provide referential significance for the exploration and fabrication of new and efficient g-C3N4-based heterostructure. [ABSTRACT FROM AUTHOR]

A series of Z-scheme CuSnO3/g-C3N4 heterojunctions were synthesized by a precipitation–calcination method. Morphological features, chemical composition, optical properties and crystallographic information of the prepared materials were obtained using scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV–Vis diffuse reflection spectroscopy (UV-Vis DRS), and photoluminescence spectroscopy (PL). The as-fabricated catalysts assisted by H2O2 showed remarkably enhanced photocatalytic performance for the degradation of tetracycline (TC) under visible light irradiation. The 20 wt% CuSnO3/g-C3N4 composite exhibited the highest photocatalytic degradation activity, which could be up to 93.6% at 60 min for the degradation of TC under visible light irradiation. Reactive species scavenging experiments revealed that superoxide radicals were the main active species during the photocatalytic process. This work will be useful for the design of other direct Z-scheme photocatalytic systems for applications in energy conversion and environmental remediation. [ABSTRACT FROM AUTHOR]

The photocatalytic degradation mechanism of Ag 2 ZnGeO 4 /g-C 3 N 4. [Display omitted] • Ag 2 ZnGeO 4 /g-C 3 N 4 binary photocatalysts were successfully prepared by wet impregnation. • The formation of heterojunction improved the optical properties of g-C 3 N 4. • The Ag 2 ZnGeO 4 /g-C 3 N 4 exhibited excellent photodegradation of TC. • Superoxide anion radicals played an essential role in the photocatalytic degradation of TC. • A possible Z-scheme of the photocatalytic degradation mechanism was proposed. Accumulation of tetracycline was hazardous to human health and ecosystems. Ag 2 ZnGeO 4 /g-C 3 N 4 heterojunction photocatalysts were successfully prepared by the wet impregnation method. The morphological structure and optical properties of the photocatalysts were measured by a series of characterization methods. Moreover, Ag 2 ZnGeO 4 /g-C 3 N 4 with a loading ratio of 20 % exhibited excellent photocatalytic activity by exploring the Ag 2 ZnGeO 4 loading, catalyst dosage, initial concentration, and initial pH of tetracycline. The degradation efficiency of 20 % Ag 2 ZnGeO 4 /g-C 3 N 4 for 10 mg/L TC was 94.29 % at 0.2 g/L catalyst dosage, and the corresponding first-order reaction rate constant reached a maximum of 0.0199 min−1. In addition, according to the results of the trapping experiments, superoxide anion radical was the major active species. Eventually, a possible Z-scheme of the photocatalytic degradation mechanism was proposed. The heterojunction formed between Ag 2 ZnGeO 4 and g-C 3 N 4 could accelerate the transfer and separation of photogenerated carriers, enhancing the photocatalytic activity. [ABSTRACT FROM AUTHOR]

A highly efficient binary CdIn2S4/g-C3N4 heterojunction photocatalyst was synthesized by a simple wet impregnation method. Photocatalytic system based on the synergistic action of binary CdIn2S4/g-C3N4 heterojunction and H2O2 was proposed to improve the degradation effect of dyes. The photocatalytic activity was evaluated by the degradation of methyl orange(MO) under visible light irradiation. The results demonstrated that contrasted to pure g-C3N4, the synthesized heterojunction can significantly improve the photocatalytic activity. After 120 min of irradiation by visible light, the photocatalytic efficiency of MO degradation of 7CIS/CN was 3.13 times higher than that of g-C3N4. When 60 mM H2O2 was added on this basis, the photocatalytic efficiency increased from 93.81 to 99.40%. The improvement of photocatalytic activity is attributed to the formation of binary CdIn2S4/g-C3N4 heterojunction to promote the transfer of photogenerated electron-hole pairs, and an appropriate amount of H2O2 as an electron trap further reduced the recombination rate of photogenerated electron-hole pairs. Active species capture experiments showed that ·O2− are the main active substances. Subsequently, the mechanism of photocatalytic degradation was proposed. This work provided a new efficient strategy for the degradation of industrial dye wastewater. [ABSTRACT FROM AUTHOR]

BiOI/g-C3N4 binary catalysts with different loading ratios were prepared by a mild one-step stirring method. The optimum loading ratio of BiOI was selected by photocatalytic degradation of 20 mg/L methyl orange (MO) under visible light irradiation. The experimental results of photocatalytic degradation of MO indicated that the loading of BiOI improves the photocatalytic performance of g-C3N4. The structure and morphology of the catalyst were examined by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet–visible (UV–vis) diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PL) and fourier transform infrared spectroscopy (FT-IR). The characterization results showed that BiOI and g-C3N4 were well complexed together, the Z-type heterojunction between them increased the utilization of visible light by g-C3N4 and reduced the recombination rate of photogenerated electron–hole pairs. In addition, the effects of catalyst loading, initial concentration of solution and initial pH on the photocatalytic degradation of MO by BiOI/g-C3N4 under visible light were explored. As a result, it was found that the optimum dosage of the binary catalyst was 1.25 g/L, and the photocatalytic efficiency against MO decreased as the initial concentration increased. In addition, the initial pH of the MO solution had a complicated effect on the photocatalytic efficiency of the binary catalyst, which was related to the existence form of MO in different environments. Finally, the main factors of photocatalytic degradation of MO were confirmed by free radical trapping experiments. Based on the results, the possible mechanism of photocatalytic degradation of MO by BiOI/g-C3N4 was inferred. Enhanced visible light photocatalytic activity was obtained due to light trapping of photogenerated carriers, high transfer efficiency, and enhanced separation efficiency by Z-type heterojunction. [ABSTRACT FROM AUTHOR]

Herein, the ternary CdS/Zn 2 In 2 S 5 /g-C 3 N 4 (CdS/ZIS/CN) heterojunction photocatalyst was successfully prepared via a one-pot method for photodegradation of tetracycline (TC) under visible light irradiation. The surface morphology, structure and optical properties of the prepared photocatalytic material were analyzed by XRD, SEM, TEM, UV–vis DRS, FT-IR and PL. Moreover, the experimental results exhibited that the ternary CdS/ZIS/CN photocatalyst revealed excellent photocatalytic activity compared with g-C 3 N 4. In this work, 94.73% of TC (20 mg/L, pH=11) was degraded by 0.5 g/L 30CdS/ZIS/CN within 60 min of visible light irradiation. Additionally, the degradation rate of the photocatalyst decreased by about 9.41% after the fourth cycle, indicating its high stability and reusability. Subsequently, a possible double type-II mechanism of photodegradation was eventually provided based on active radical capture experiments. The current investigation provided a promising strategy to construct the high-efficiency heterojunction photocatalyst to degrade antibiotic contaminants. [Display omitted] • A ternary CdS/Zn 2 In 2 S 5 /g-C 3 N 4 heterojunction photocatalyst was synthesized by a one-pot method. • The CdS/Zn 2 In 2 S 5 /g-C 3 N 4 heterojunction revealed excellent an excellent degradation rate of tetracycline with 94.73%. • The CdS/Zn 2 In 2 S 5 /g-C 3 N 4 heterojunction exhibited a double type-II mechanism. [ABSTRACT FROM AUTHOR]

In this study, a novel zinc sodium molybdate/graphite phase carbon nitride (Na 1.8 Zn 2.1 Mo 3 O 12 /g-C 3 N 4) heterostructure was synthesized by wet impregnation. The photocatalyst was characterized in detail from different phase purity, crystal structure, morphology, microstructure, optical properties, and showed that the preparation was successful. The effects of the loading amount of Na 1.8 Zn 2.1 Mo 3 O 12 , the initial concentration of pollutants, the amount of catalyst and the pH value on the reaction system were also discussed. The results of photocatalytic study showed that the photocatalytic activity of the synthesized Na 1.8 Zn 2.1 Mo 3 O 12 /g-C 3 N 4 photocatalyst for tetracycline (TC) under visible light treatment was better than that of the pure g-C 3 N 4 and Na 1.8 Zn 2.1 Mo 3 O 12. The improved catalytic activity can be attributed to the formation of heterojunction between Na 1.8 Zn 2.1 Mo 3 O 12 and g-C 3 N 4 and the effective separation of photogenerated electron hole pairs. The capture tests confirmed that superoxide radical (·O 2 -) and photogenerated hole (h+) are the main active species involved in the photocatalytic reaction. Finally, the possible mechanism of the synergistic effect of g-C 3 N 4 and Na 1.8 Zn 2.1 Mo 3 O 12 to improve the photocatalytic performance was studied. • A novel visible light responsive Na 1.8 Zn 2.1 Mo 3 O 12 photocatalysts were fabricated by hydrothermal and calcination method. • The introduction of Na 1.8 Zn 2.1 Mo 3 O 12 optimized the separation rate of photogenerated electron hole pairs in g-C 3 N 4. • Na 1.8 Zn 2.1 Mo 3 O 12 /g-C 3 N 4 presented excellent photocatalysis and photochemical stability towards degradation of tetracycline. • The electron transfer mechanism and possible degradation mechanism between Na 1.8 Zn 2.1 Mo 3 O 12 and g-C 3 N 4 were discussed. [ABSTRACT FROM AUTHOR]

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]

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]