Bi Yuanqing, Wang Yu, Dong Xiaoli, Zheng Nan, Ma Hongchao, Zhang Xiufang
School of Light Industry and Chemical Engineering, Dalian Polytechnic University #1 Qinggongyuan Dalian 116034 P. R China
RSC Adv. 2018 Jun 13;8(39):21871-21878. doi: 10.1039/c8ra02483a.
Solar-driven reduction of dinitrogen to ammonia under mild conditions has attracted widespread interest in recent years. In this study, we first report low-temperature hydrogenated BiOBr for the direct synthesis of ammonia from dinitrogen with high efficiency under solar-light irradiation. In a proof of concept, the hydrogenation treatment can lead to surface disorder due to the strong reducing capacity of hydrogen. Oxygen atoms can be activated, and they can escape from the surface structure to form oxygen vacancies. Then, defect engineering can broaden the photoelectricity absorption window and effectively trigger interfacial electron transfer from the semiconductor to the combined nitrogen. This method exhibits a satisfactory result for photocatalytic nitrogen fixation, yielding about 2.6 times more NH than that obtained from the original sample. The corresponding apparent quantum efficiency can reach a significant value of 2.1% under 380 nm monochromatic light irradiation. These results may pave a new way for the synthesis of highly active photocatalysts for efficient nitrogen fixation under solar light irradiation.
近年来，温和条件下太阳能驱动的氮气还原制氨引起了广泛关注。在本研究中，我们首次报道了低温氢化的BiOBr，用于在太阳光照射下高效地从氮气直接合成氨。在概念验证中，由于氢的强还原能力，氢化处理会导致表面无序。氧原子可以被激活，并从表面结构中逸出形成氧空位。然后，缺陷工程可以拓宽光电吸收窗口，并有效地触发从半导体到结合氮的界面电子转移。该方法在光催化固氮方面表现出令人满意的结果，产生的NH比原始样品多约2.6倍。在380 nm单色光照射下，相应的表观量子效率可达到2.1%的显著值。这些结果可能为在太阳光照射下合成用于高效固氮的高活性光催化剂开辟一条新途径。
