Photocatalytic properties of RuO2-loaded β-Ge3N4 for overall water splitting
Photocatalytic properties of RuO2-loaded β-Ge3N4 for overall water splitting
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DOI：
10.1021/jp067254c
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发表时间：
2007-03-29
影响因子：
3.7
通讯作者：
Domen, Kazunari
中科院分区：
文献类型：
--
作者：
Maeda, Kazuhiko;Saito, Nobuo;Domen, Kazunari
研究了氮化锗β-Ge 3 N4作为非氧化物光催化剂用于整体水分解。GeO 2在1153 K下的NH3气流中氮化10 h，得到结晶良好的β-Ge 3 N4颗粒，其结构为六方晶系的菲安山岩结构。尽管如此制备的β-Ge 3 N4显示出可忽略的整体水分解活性，但当负载RuO 2纳米颗粒作为H-2析出位点时，该材料在紫外（UV）照射（λ> 200 nm）下变得具有光催化活性。RuO 2负载的β-Ge 3 N4的光催化活性的整体水裂解是强烈依赖于反应条件。当反应在1 M H2SO 4水溶液中进行时，获得最高活性。随着反应的进行，H-2和O-2的释放速率降低，这归因于O-2的光还原、Ge阳离子的迁移导致的催化剂表面的坍塌以及β-Ge 3 N4和负载的RuO 2纳米颗粒之间的界面接触松动。高达80%的初始活性可以通过煅烧的使用过的催化剂在673 K在空气中为5小时，然后重新加载RuO 2恢复。
Germanium nitride, beta-Ge3N4, is studied as a non-oxide photocatalyst for overall water splitting. Nitridation of GeO2 at 1153 K for 10 h under a flow of NH3 results in the production of well-crystallized beta-Ge3N4 particles with a phenacite structure belonging to the hexagonal crystal system. Although the as-prepared beta-Ge3N4 displays negligible activity for overall water splitting, the material becomes photocatalytically active under ultraviolet (UV) irradiation (lambda > 200 nm) when loaded with RuO2 nanoparticles as H-2 evolution sites. The photocatalytic activity of RuO2-loaded beta-Ge3N4 for overall water splitting is strongly dependent on the reaction conditions. The highest activity is obtained when the reaction is carried out in 1 M H2SO4 aqueous solution. The rates of both H-2 and O-2 evolution decreases as the reaction progresses, attributable to photoreduction of O-2, collapse of the catalyst surface by elusion of Ge cations, and loosened interfacial contact between the beta-Ge3N4 and the loaded RuO2 nanoparticles. Up to 80% of the initial activity can be recovered by calcination of the used catalyst at 673 K in air for 5 h followed by reloading with RuO2.