Zinc germanium oxynitride as a photocatalyst for overall water splitting under visible light
Zinc germanium oxynitride as a photocatalyst for overall water splitting under visible light
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DOI：
10.1021/jp0656532
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发表时间：
2007-01-18
影响因子：
3.7
通讯作者：
Yashima, Masatomo
中科院分区：
文献类型：
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作者：
Lee, Yungi;Terashima, Hiroaki;Yashima, Masatomo
氧化锌和氮化锗（Zn（1+x）Ge）（N（2）O（x））（x = 0.44）的固溶体被证明是一种有效的光催化剂，用于在紫外和可见光下的整体水分解。以GeO（2）和ZnO为原料，在20 mL氨气流中反应制得催化剂。min（-1）），反应15 h。材料的晶体结构的研究相结合的Rietveld分析和最大熵方法使用中子粉末衍射数据。确认了（Zn（1.44）Ge）（N（2.08）O（0.38））催化剂具有纤锌矿型结构（空间群P6（3）mc），并且是其中氧原子取代氮原子的固溶体。由此制备的（Zn（1.44）Ge）（N（2.08）O（0.38））催化剂表现出约为0.38的带隙。2.7 eV和可见波长处的相应活性。与起始材料相比，带隙的减小归因于由O2 p和N2 p轨道之间的能量差以及上价带中Zn 3d和N2 p + O2 p电子之间的p-d排斥引起的较大的价带色散，这提高了价带的顶部。（Zn（1.44）Ge）（N（2.08）O（0.38））粉末通过表面负载5wt%的RuO（2）纳米颗粒进行改性，在紫外和可见光照射下实现了整体水分解。
A solid solution of zinc oxide and germanium nitride (Zn(1+x)Ge)(N(2)O(x)) (x = 0.44) is demonstrated to be an effective photocatalyst for overall water splitting under ultraviolet and visible light. The catalyst is prepared by reaction of GeO(2) and ZnO under ammonia flow (20 mL(.)min(-1)) at 1123 K for 15 h. The crystal structure of the material is investigated by a combination of Rietveld analysis and the maximum-entropy method using neutron powder diffraction data. The (Zn(1.44)Ge)(N(2.08)O(0.38)) catalyst is confirmed to have a wurtzite-type structure (space group P6(3)mc) and to be the solid solution where the oxygen atoms are substituted for nitrogen atoms. The (Zn(1.44)Ge)(N(2.08)O(0.38)) catalysts thus prepared exhibit a band gap of ca. 2.7 eV and corresponding activity at visible wavelengths. The decrease in band gap compared to the starting materials is attributed to larger valance band dispersion resulting from the energy difference between O2p and N2p orbitals and from the p-d repulsion between Zn3d and N2p+O2p electrons in the upper valance band, which raises the top of the valance band. (Zn(1.44)Ge)(N(2.08)O(0.38)) powder modified by surface loading with RuO(2) nanoparticles at 5 wt % achieves overall water splitting under both ultraviolet and visible irradiation.