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A highly efficient MgBi2O6 (MBO)/TiO2 heterostructured photocatalyst for the evolution of H2 was successfully prepared using a one-step hydrothermal method. The phase structure, microstructure and optical properties of the MBO/TiO2 composites were investigated by various experimental techniques. A series of H2 production experiments were performed under visible light. The measured results indicated that the nanostructured MBO/TiO2 composite, with a stoichiometric molar ratio of MBO:TiO2 = 0.2%, displayed the best H2 production rate of 3413 μmol h−1 g−1. The excellent photocatalytic performance of the obtained composite material was due to the heterojunction formed between MBO and TiO2, which reduced the charge transfer resistance and accelerated the separation efficiency of the photogenerated electron–hole pairs. The reaction mechanism was also discussed in detail. [ABSTRACT FROM AUTHOR]

The pyrochlore-type (Sr0.6Bi0.305)2Bi2O7 (SBO), containing Bi3+ and Bi5+ mixed valent states, was recently found to be used as a new visible light responsive photocatalyst. Novel SBO/SnO2 heterostructured composites were synthesized through a facile one-step hydrothermal method. The phase structure, morphology, chemical composition, and optical properties of the obtained samples were characterized by XRD, SEM, TEM, XPS, and UV-vis DRS. Compared to pure SBO and SnO2, the synthesized SBO/SnO2 composites exhibited significantly enhanced photocatalytic efficiency. The results indicated that the photoinduced holes and superoxide radicals play a dominant role and are the main reactive species during the degradation of Methylene Blue (MB) solution under visible light irradiation. Heterojunctions, formed in samples, directly contribute to the improvement of photocatalytic efficiency of SBO/SnO2 composites, since it not only broadens the light response range, but also accelerates the separation of photogenerated carriers. [ABSTRACT FROM AUTHOR]

[Display omitted] • Heterostructured CaCO 3 /NiS composites were synthesized via the facile hydrothermal method. • CaCO 3 /NiS showed the significantly enhanced photocatalytic bactericidal performance. • The active OH and O 2 – cooperate with vacancies to enhance bactericidal performance of CaCO 3 /NiS. CaCO 3 /NiS heterostructured composites were synthesized via the facile hydrothermal method. CaCO 3 /NiS showed the best photocatalytic bactericidal performance when the addition was 15 mg. Under 10 min visible light irradiation, about 90 % of Staphylococcus aureus was killed by composite, which was 4.5 times and 3 times faster than CaCO 3 and NiS. The addition of CaCO 3 significantly improves the photocurrent response and electron-hole pair separation rate of NiS and effectively increases the yield of active free radical groups. These groups cause the bacterial cell membrane to be destroyed and the internal proteins to be flow out, achieving the effect of killing bacteria. The solitary electron pair in the CaCO 3 /NiS composite absorbs visible light energy, making lots of atoms leave the equilibrium check point and effectively preventing the recombination of photogenerated electrons and holes. The inherent active substances (OH and O 2 –) cooperate with vacancies to enhance bactericidal performance. The design and synthesis of CaCO 3 /NiS composites effectively improve the sterilization effect and its application can be expected. [ABSTRACT FROM AUTHOR]