Wang Xuefei, Cheng Jingjing, Yu Huogen, Yu Jiaguo
School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, PR China.
Dalton Trans. 2017 May 16;46(19):6417-6424. doi: 10.1039/c7dt00773f.
Carbon dots (CDs)/g-CN is a promising photocatalyst to split water for H production; however, the synthesis of CDs/g-CN is usually rigorous and involves multiple steps, which limits its practical application. In this study, a facile hydrothermal approach was developed to prepare CDs/g-CN photocatalysts using l-ascorbic acid and g-CN as the precursors. Upon in situ thermal polymerization of l-ascorbic acid on the g-CN surface, the carbon dots were homogeneously and solidly modified on the g-CN surface. The CDs/g-CN photocatalysts showed higher photocatalytic performance for H production than g-CN under UV light irradiation using lactic acid as the sacrificial agent. The improved photocatalytic performance of CDs/g-CN was mainly attributed to rapid interfacial charge transfer. After a Pt co-catalyst was loaded, the Pt-CDs/g-CN catalyst formed exhibited a further improved photocatalytic performance for H production and could even split pure water to produce H. Considering our present economic and facile synthetic approach for the modification of carbon dots on the surface of g-CN photocatalysts, the as-prepared CDs/g-CN photocatalysts will be promising for practical use in water splitting.
碳点(CDs)/石墨相氮化碳(g-CN)是一种很有前景的用于光解水制氢的光催化剂;然而,CDs/g-CN的合成通常较为苛刻且涉及多个步骤,这限制了其实际应用。在本研究中,开发了一种简便的水热法,以l-抗坏血酸和g-CN为前驱体制备CDs/g-CN光催化剂。通过l-抗坏血酸在g-CN表面原位热聚合,碳点均匀且牢固地修饰在g-CN表面。在以乳酸为牺牲剂的紫外光照射下,CDs/g-CN光催化剂比g-CN表现出更高的光催化产氢性能。CDs/g-CN光催化性能的提高主要归因于快速的界面电荷转移。负载Pt助催化剂后,形成的Pt-CDs/g-CN催化剂对产氢表现出进一步提高的光催化性能,甚至可以光解纯水制氢。考虑到我们目前用于在g-CN光催化剂表面修饰碳点的经济且简便的合成方法,所制备的CDs/g-CN光催化剂在水分解的实际应用中具有广阔前景。