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Photocatalysis provides a sustainable route to convert N 2 to NH 3 with the aid of a photogenerated electron. Beyond the typical issue in the photocatalytic field, NH 3 synthesis requires adsorption, activation, and hydrogenation of N 2 . In this report, Ni-doped TiO 2 (Ni-x-TiO 2 ) photocatalysts were fabricated by a simple sol−gel method to introduce the oxygen defects and Ni site on TiO 2 . The oxygen vacancy (Vo) enhances the adsorption of N 2 on the catalyst surface. The Ni doping induced a defect energy level below the conduction band, which prefers to accept the photogenerated electron. The electron captured by Vo tends to transfer to the adsorbed N 2 and activate N 2 . On the other hand, the Ni site is a typical H 2 production site. It provides enough H 2 for the hydrogenation of N 2 to form NH 3 . To sum up all of these advantages, Ni-doped TiO 2 displays a high NH 3 production rate of 46.80 μmol•g −1 •h −1 which is about 7 times higher than that of pure TiO 2 . This manuscript provides a potential method to design a highly efficient photocatalyst for the NH 3 synthesis.

In this work, compared with the corresponding pure CsPbCl3 nanocrystals (NCs) and Mn2+-doped CsPbCl3 NCs, Mn2+/Cu2+-codoped CsPbCl3 NCs exhibited improved photoluminescence (PL) and photoluminescence quantum yields (PL QYs) (57.6%), prolonged PL lifetimes (1.78 ms), and enhanced thermal endurance (523 K) as a result of efficient Mn2+ doping (3.66%) induced by the addition of CuCl2. Furthermore, we applied pressure on Mn2+/Cu2+-codoped CsPbCl3 NCs to reveal that a red shift of photoluminescence followed by a blue shift was caused by band gap evolution and related to the structural phase transition from cubic to orthorhombic. Moreover, we also found that under the preheating condition of 523 K, such phase transition exhibited obvious morphological invariance, accompanied by significantly enhanced conductivity. The pressure applied to the products treated with high temperature enlarged the electrical difference and easily intensified the interface by closer packaging. Interestingly, defect-triggered mixed ionic and electronic conducting (MIEC) was observed in annealed NCs when the applied pressure was 2.9 GPa. The pressure-dependent ionic conduction was closely related to local nanocrystal amorphization and increased deviatoric stress, as clearly described by in situ impedance spectra. Finally, retrieved products exhibited better conductivity (improved by 5–6 times) and enhanced photoelectric response than those when pressure was not applied. Our findings not only reveal the pressure-tuned optical and electrical properties via structural progression but also open up the promising exploration of more amorphous all-inorganic CsPbX3-based photoelectric applications.

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Highly dispersed ZnO/g-C3N4 composites with different doping ratios of g-C3N4 were prepared by a hydrothermal method. The preparation method is simple and the energy consumption is low. The composite samples were used to degradate the methyl orange solution. They all showed excellent photocatalytic activity and cycling stability. The optimal loading content of g-C3N4 was investigated, and the mechanism of enhanced photocatalytic activity was studied in detail. This study provides a promising photocatalytic material for the removal of organic pollutants.