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The Zn2+ doped In2.77S4 (Zn–In2.77S4) photocatalyst has been synthesized via a one-step hydrothermal method. The tetracycline was adopted to measure the photocatalytic performance of the as-fabricated Zn–In2.77S4 composites. The probable photocatalytic degradation mechanism of the as-prepared composites was also discussed. Experimental results reveal that doping Zn2+ into In2.77S4 can broaden the light absorption range and improve the recycle ability as well as the separation efficiency of photo-generated electron–hole pairs of pure In2.77S4. Moreover, as the doping amount of Zn2+ increased the photocatalytic efficiency of the as-obtained Zn–In2.77S4 composites appears the tendency of firstly increasing and then decreasing. When the molar ratio of Zn2+ to In3+ is 0.04:1 (4%), in 15 min, the photocatalytic efficiency of the as-developed Zn–In2.77S4 photocatalyst reaches to the maximum of 90.0%. It is higher than 31.8% of pure In2.77S4. Furthermore, superoxide radicals and holes play major roles in the process of photodegradation tetracycline. This research can supply a promising guide to solve antibiotics pollution in water under sunlight.

The In2.77S4/SrCO3 heterojunction photocatalyst had been prepared by one-step hydrothermal method. X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectrometry, UV–Vis diffuse reflectance spectroscopy and electrochemical impedance spectroscopy were used to analyze the structure, morphology, chemical compositions, optical properties and charge carrier behaviors of the as-prepared In2.77S4/SrCO3 hybrids, respectively. Experimental results revealed the SrCO3 could obviously improve the recyclability and photocatalytic activities of In2.77S4 nanosheets for both methyl orange and tetracycline oxidation under visible light. The photocatalytic degradation efficiency of the as-obtained In2.77S4/SrCO3 hybrids was first increased and then decreased with increasing the molar ratio of Sr(NO3)2 to In(NO3)3·4.5H2O. When it was 0.4:1, that of the as-prepared hybrids with the band gap of 1.63 eV reached the maximum of 96.0% in 30 min for methyl orange and 82.7% in 20 min for tetracycline. These were higher than 88.0% and 40.0% of In2.77S4 nanosheets as well as 0.8 and 1.8% of SrCO3 particles, respectively. After three cycles, its photocatalytic efficiency still possessed 92.7% for methyl orange and 80.3% for tetracycline, which were much higher than 35.3% and 11.3% of In2.77S4 nanosheets. Moreover, the possible photocatalytic degradation mechanism of the In2.77S4/SrCO3 hybrids was also proposed.

SnS2/few layer boron nitride nanosheets composites were synthesized via a one-step hydrothermal method. The as-prepared samples were characterized by X-ray diffraction, transmission electrical microscopy, UV–vis diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, photoluminescence emission spectra and electrochemical impedance spectroscopy, respectively. Rhodamine B was adopted to evaluate the degradation efficiency of the as-prepared samples under visible light irradiation. Experimental results showed that, compared to pure SnS2, the few layer boron nitride nanosheets could improve photocatalytic activities of the samples for the degradation of Rhodamine B. With increasing the usage amount of the few layer boron nitride nanosheets, the degradation efficiency was first increased and then decreased. When the usage amount of the few layer boron nitride nanosheets was 10 wt%, it exhibited the highest degradation efficiency of 93.7% in 210 min, which was higher than 50% of pure SnS2. After it was recycled for four times, it still possessed 88.7% of degradation efficiency. This was increased by 1008.7% than pure SnS2. Moreover, it had band gap energy of 1.78 eV, obviously smaller than 2.06 eV of pure SnS2. In addition, a possible photocatalytic mechanism was also presented.