掺杂二氧化钛/碳的制备及可见光催化制氢

Preparation of Doped TiO_(2)/Carbon and Visible-Light Catalytic Hydrogen Production

采用深度低共熔溶剂为前驱体,通过一步热解法制备N,O掺杂多孔碳纳米片原位复合N,C掺杂TiO_(2)异相结光催化剂。所得多孔异相结提供了更高的比表面积和更多活性位点。高温形成的锐钛矿相和金红石相TiO_(2),构成异相结,有利于光生电子和空穴的分离,抑制光生载流子重组。此外,TiO_(2)与碳纳米片复合,光生电子转移到碳纳米片表面,进一步分离光生电子和空穴。元素掺杂两相TiO_(2),使禁带宽度变窄,拓宽了对可见光的吸收利用,提高了光催化还原水析氢活性。在可见光析氢测试中,产氢速率达到28.7 mmol·(g·h)^(-1),是单独使用锐钛矿TiO_(2)的29.3倍。

In situ composite of N,O-doped porous carbon nanosheets with N,C-doped TiO_(2)heterojunction photocatalyst were prepared by one-step pyrolysis using a deep eutectic sol-vent as precursors.The resulting porous heterojunction provides higher specific surface area and more active sites.The anatase and rutile TiO_(2)formed at high temperature form phase junction,which is beneficial to the separation of photogenerated electrons and holes,and in-hibits the recombination of photogenerated carriers.Element-doped two-phase TiO_(2)narrows the forbidden band width,broadens the absorption and utilization of visible light,and im-proves the photocatalytic reduction of water for hydrogen evolution.In addition,TiO_(2)com-posites with carbon nanosheets,and photogenerated electrons are transferred to the surface of carbon nanosheets,which further promotes the separation of photogenerated electrons and holes.The photocatalytic hydrogen production rate reached 28.7 mmol·(g·h)^(-1),under visible light,which is 29.3 times that of anatase TiO_(2)alone.