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NaNb x Ta 1-x O 3 , sodium tantalate and niobate with B atoms substitution is synthesized by a facile one-step hydrothermal method. They are effective photocatalysts for hydrogen evolution from water splitting without co-catalyst. NaNb 0.33 Ta 0.67 O 3 exhibits the best performance with produced H 2 of 1038 μmol g−1 in 5 h, which is more than 5 times than NaTaO 3 and NaNbO 3. It is also close to 5 times and 2 times than NaTaO 3 /Pt and NaNbO 3 /Pt, respectively. NaNb 0.33 Ta 0.67 O 3 has a transition state crystal structure between NaTaO 3 and NaNbO 3 crystalline phase. Moreover, XPS, ESR and TEM characterizations demonstrates that there are abundant oxygen vacancies in NaNb 0.33 Ta 0.67 O 3. These features give the catalyst excellent properties, such as good light harvesting and efficient charge separation confirmed by optical and electrochemical characterizations. This work may offer a strategy to develop perovskite sodium tantalate and niobate with controllable crystal structure and oxygen vacancies for highly efficient photocatalytic hydrogen evolution in the absence of co-catalyst. [Display omitted] • NaNb x Ta 1-x O 3 photocatalysts were prepared by a facile hydrothermal method. • NaNb x Ta 1-x O 3 had superior photocatalytic H 2 evolution ability without co-catalyst. • The maximum yield of H 2 was 1038 μmol. g−1 over NaNb 0.33 Ta 0.67 O 3 in 5 h. • Produced H 2 over NaNb 0.33 Ta 0.67 O 3 was more than 5 times than NaTaO 3 and NaNbO 3. • Excellent performance depended on transition state structure and oxygen vacancy. [ABSTRACT FROM AUTHOR]

The Ag 2 O/Ag 2 CO 3 heterostructure photocatalysts synthesized and regulated using simple one-step solid-state chemical process at room temperature exhibited outstanding visible light-driven photocatalytic acivity. • The heterojunction were in situ constructed by one-step room temperature solid-state method. • The composition of heterojunction can be in situ regulated by solid-state method. • The regulation mechanism of heterojunction has also been revealed. • The obtained Ag 2 O/Ag 2 CO 3 displays outstanding photocatalytic activity and reusability. Ag-based photocatalysts have excellent photocatalytic properties, but their photocatalytic degradation performance is limited by the serious photocatalytic corrosion. In order to enhance the stability of photocatalytic degradation of Ag-based photocatalysts, here, the Ag 2 O/Ag 2 CO 3 heterojunction was in-situ constructed and conveniently regulated by controlling the alkalinity of room temperature solid-state chemical reaction system. The photocatalytic degradation activity of the obtained heterojunction was influenced by the in-situ regulated component and band position of the Ag 2 O/Ag 2 CO 3 heterojunction. The obtained optimal products AAC-6 displayed remarkable photocatalytic activity and high reusability. The apparent rate constant of AAC-6 is 20 times than that of Ag 2 CO 3 , it is also far higher than that of P25. The significantly enhanced photocatalytic performance can be ascribed to the matching energy position between Ag 2 CO 3 and Ag 2 O, which can facilitate the visible light absorption ability and the efficient separation of photoinduced charges carriers. This study explored an in-situ one-step solid-state strategy to construct Ag 2 CO 3 -based heterojunction catalyst with outstanding photocatalytic performance, which may open a new perspective for the preparation of excellent photocatalytic degradation materials by solid-state chemical method. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, α-Fe2O3 nanorings were synthesized and used as a support to further synthesize hybrid Pt/α-Fe2O3 nanorings. Transmission electron microscopy (TEM) analyses clearly suggest that Pt nanoparticles are deposited on the surface of α-Fe2O3 nanorings in a well-dispersed state. This metal–semiconductor hybrid system is expected to show high photocatalytic activity towards the degradation of environmental pollutants. Because of the Schottky contact between semiconductor and metal particles, the holes prefer to localize in energetically lower semiconductor, whereas the electrons can move through the heterointerface. This interfacial charge transfer and separation facilitate the redox reactions, results in a high photocatalytic activity. In our case, the as obtained α-Fe2O3/Pt hybrids exhibit enhanced photocatalytic performance with a degradation rate of 86.7% for methyl orange, which is much higher than that of pure α-Fe2O3 (33.2%). [Copyright &y& Elsevier]

An interesting and ultra-simple organic molecule adsorption strategy was used to simultaneously increase the reduction ability of photogenerated electrons and light absorption of commercial TiO 2. Experimental and DFT theoretical calculations verified that the adsorbed organics can provide electrons for TiO 2 , the pre-provided electrons enable the conduction band bend upwards, thus enhance the reduction ability of photogenerated electrons and improve the light absorption ability of TiO 2. So the resulted photocatalytic performance increased by 43 times. • The ultra-simple adsorption strategy increases photocatalytic performance by 43 times. • The interesting strategy can simultaneously narrow band gap and increase conduction band position. • The electron supply mechanism is verified by experimental and DFT caculation results. The photogenerated electron reduction ability and light absorption capacity of photocatalysts are crucial to their photocatalytic hydrogen evolution performance. However, rising the conduction band position will widen the band gap and result in a decrease in light absorption efficiency. Herein, an ultra-simple and novel organic molecule adsorption strategy was carried out on the surface of commercial TiO 2 to simultaneously increase the reduction ability of photogenerated electrons and light absorption of commercial TiO 2. Then the contradiction mentioned above was perfectly solved by such an interesting strategy. The resultant ethylenediamine adsorbed TiO 2 exhibits excellent photocatalytic hydrogen evolution rate, which is 43 times higher than that of commercial TiO 2. Effectively, the experimental results and DFT theoretical calculations verified that the adsorbed organic molecule can provide electrons for TiO 2. The provided electrons enable the conduction band bend upwards, thus enhance the reduction ability of photogenerated electrons and improve the light absorption ability of TiO 2. More interestingly, the provided electrons can also promote the separation efficiency of photogenerated carriers by weakening the attraction of photogenerated holes to photogenerated electrons. Therefore, the efficiency of photocatalytic hydrogen production has been greatly improved. This work opens a new research field to enhance the photocatalytic performance by adsorbing various designed organics on the surface of photocatalysts. [ABSTRACT FROM AUTHOR]