Robust Co-catalytic Performance of Nanodiamonds Loaded on WO3 for the Decomposition of Volatile Organic Compounds under Visible Light

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• 作者：Hyoung−il Kim ; Hee-na Kim ; Seunghyun Weon ; Gun-hee Moon ; Jae-Hong Kim ; Wonyong Choi
• 刊名：ACS Catalysis
• 出版年：2016
• 出版时间：December 2, 2016
• 年：2016
• 卷：6
• 期：12
• 页码：8350-8360
• 全文大小：672K
• ISSN：2155-5435

文摘

Proper co-catalysts (usually noble metals), combined with semiconductor materials, are commonly needed to maximize the efficiency of photocatalysis. Search for cost-effective and practical alternatives for noble-metal co-catalysts is under intense investigation. In this work, nanodiamond (ND), which is a carbon nanomaterial with a unique sp<sup>3sup>(core)/sp<sup>2sup>(shell) structure, was combined with WO<sub>3sub> (as an alternative co-catalyst for Pt) and applied for the degradation of volatile organic compounds under visible light. NDs-loaded WO<sub>3sub> showed a highly enhanced photocatalytic activity for the degradation of acetaldehyde (∼17 times higher than bare WO<sub>3sub>), which is more efficient than other well-known co-catalysts (Ag, Pd, Au, and CuO) loaded onto WO<sub>3sub> and comparable to Pt-loaded WO<sub>3sub>. Various surface modifications of ND and photoelectochemical measurements revealed that the graphitic carbon shell (sp<sup>2sup>) on the diamond core (sp<sup>3sup>) plays a crucial role in charge separation and the subsequent interfacial charge transfer. As a result, ND/WO<sub>3sub> showed much higher production of OH radicals than bare WO<sub>3sub> under visible light. Since ND has a highly transparent characteristic, the light shielding that is often problematic with other carbon-based co-catalysts was considerably lower with NDs-loaded WO<sub>3sub>. As a result, the photocatalytic activity of NDs/WO<sub>3sub> was higher than that of WO<sub>3sub> loaded with other carbon-based co-catalysts (graphene oxide or reduced graphene oxide). A range of spectroscopic and photo(electro)chemical techniques were systematically employed to investigate the properties of NDs-loaded WO<sub>3sub>. ND is proposed as a cost-effective and practical nanomaterial to replace expensive noble-metal co-catalysts.