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Highly active and efficient photocatalysts are crucial for the exploration of ammonia synthesis because of the serious problem of energy deficiency. La 2 TiO 5 (LTO) perovskite materials have great advantages in the field of photocatalytic nitrogen fixation because of the broadly diversified properties. The rational design of surface defect is a valid method to modulate photoinduced charge traps and create defect energy levels, especially it is an effective way to suppress the photoinduced charge recombination. Herein, LTO was obtained by a simple sol-gel method and was further reduced by NaBH 4 to introduce oxygen defect on its surface. UV-vis spectra proved that the surface defects could reduce the band gap value of samples, which is beneficial for improving photocatalytic nitrogen fixation activity. For the best photocatalytic samples with good cycle stability, the nitrogen fixation rate is 158.13 μmol·g -1 ·h -1 . The mechanism of photocatalytic nitrogen fixation was proposed by the PL, XPS, and PEC results, which provided possibilities for exploring more promising perovskite catalysts in the field of nitrogen fixation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Photocatalytic nitrogen fixation for the synthesis of ammonia is an important and attractive method to N2 turning into other compounds. The development of compact heterostructure photocatalysts is crucial for efficient solar energy conversion. Here, composite was obtained by simple in situ hydrothermal etching of the reduced TiO2 nanospheres with saturated calcium hydroxide solution. CaTiO3/TiO2 heterostructure composite can adsorb, activate and convert N2 to ammonia by using its close contact interface. Under simulated sunlight irradiation, CaTiO3/TiO2 composite greatly enhanced the photocatalytic N2 reduction performance. Compared with pure CaTiO3, the efficiency of 0.3-T–C heterostructure in synthesizing NH3 under visible light was 1.88 times higher than that of pure CaTiO3 (59.17 μmol·g−1·h−1) The excellent photocatalytic performance of CaTiO3/TiO2 is attributed to the close structure between CaTiO3 and TiO2, which promotes the separation of photogenerated charges and provides more active sites. This study provides a basic idea for the rational design of highly efficient heterogeneous photocatalysts to achieve excellent photocatalytic performance for N2 reduction. [ABSTRACT FROM AUTHOR]

An efficient photocatalyst capable of forming oxygen defects on the surface of mesoporous TiO2 was obtained via doping molybdenum ions which can obviously broaden the absorption range of TiO2 under visible light and reduce the recombination rate of photogenerated electron–hole pairs. The surface oxygen defects (Vo) introduced by metal molybdenum doping will adsorb and activate target molecules on the semiconductor surface. The effect of Vo content, modulated by Mo ions doping, on the photocatalytic NH3 production rates of the as-obtained samples was investigated. The optimal photocatalytic NH3 generation rate of Mo-doped TiO2 could reach 183.02 μmol·g−1·h−1 under visible light. PL and photoelectrochemical tests results demonstrated that Mo dopants could promote photogenerated carrier's separation and restrain the recombination of carriers. Furthermore, the photocatalysts also exhibited good stability in the recycling experiments for 5 runs. The enhanced photocatalytic activity is owing to the Vo defect states, created by the Mo ion-doped, which benefits to the N2 adsorption and reduction at the Ti4+ activation center during the nitrogen fixation process. [ABSTRACT FROM AUTHOR]

An efficient photocatalyst capable of forming oxygen defects on the surface of mesoporous TiO2 was obtained via doping molybdenum ions which can obviously broaden the absorption range of TiO2 under visible light and reduce the recombination rate of photogenerated electron–hole pairs. The surface oxygen defects (Vo) introduced by metal molybdenum doping will adsorb and activate target molecules on the semiconductor surface. The effect of Vo content, modulated by Mo ions doping, on the photocatalytic NH3 production rates of the as-obtained samples was investigated. The optimal photocatalytic NH3 generation rate of Mo-doped TiO2 could reach 183.02 μmol·g−1·h−1 under visible light. PL and photoelectrochemical tests results demonstrated that Mo dopants could promote photogenerated carrier's separation and restrain the recombination of carriers. Furthermore, the photocatalysts also exhibited good stability in the recycling experiments for 5 runs. The enhanced photocatalytic activity is owing to the Vo defect states, created by the Mo ion-doped, which benefits to the N2 adsorption and reduction at the Ti4+ activation center during the nitrogen fixation process. [ABSTRACT FROM AUTHOR]

High efficient photocatalytic nitrogen fixation is an alternative strategy to solve the problems of energy consumption and environmental pollution of industrial ammonia production effectively, hence the selection and modification of catalysts are very important to improve the nitrogen fixation efficiency. In this article, a straightforward Z-scheme 0D/2D CsPbBr 3 /Bi 2 WO 6 heterojunction was successfully constructed via a simple electrostatic self-assembly approach. By combining CsPbBr 3 quantum dots (CPB QDs) with ultrathin Bi 2 WO 6 (BWO) nanosheets, a large-area heterointerface of CPB QDs and BWO nanosheets was connected tightly thus shortened the charge transport distance effectively. This facilitates the efficient charge transfer between CPB and BWO through the Z-scheme interface, thereby achieving the purpose of promoting charge separation, which is well validated in differential charge. On the basis of various characterizations, the results indicated that the CPB/BWO heterojunction possessed an excellent photocatalytic nitrogen fixation performance: the production of NH 3 at 3CPB/BWO heterojunctions (126.3 μmol‧g−1‧h−1) was about 17.1 times higher than that of pure CPB QDs. The new strategy may offer a new opportunity to the exploration and the research of halide perovskite-type photo catalysts with obviously enhanced nitrogen fixation activities. [Display omitted] [ABSTRACT FROM AUTHOR]