TiO_(2)提高富碳氮化碳的光生电荷存储性能  

Photocharging Storage Capacity of C-rich Polymeric Carbon Nitrides Enhanced by TiO_(2)

作　　者：王锡慧 唐笑 刘婷婷 李艳虹 荆川 凌发令 刘俊 周贤菊 姚璐 周衡 张家忠 WANG Xihui;TANG Xiao;LIU Tingting;LI Yanhong;JING Chuan;LING Faling;LIU Jun;ZHOU Xianju;YAO Lu;ZHOU Heng;ZHANG Jiazhong(School of Science,Chongqing University of Posts and Telecommunications,Chongqing 400065,China)

机构地区：[1]重庆邮电大学理学院,重庆400065

出　　处：《高等学校化学学报》2023年第6期152-162,共11页Chemical Journal of Chinese Universities

基　　金：重庆市教育委员会科学技术研究项目(重点项目)(批准号:KJZD-K202200605);国家自然科学基金(批准号:12004061,52104392);重庆市教育委员会科学技术研究项目(批准号:KJQN202000629);重庆市自然科学基金(批准号:cstc2021jcyj-msxmX0024);重庆市教育委员会科学技术研究项目(重大项目)(批准号:KJZD-M202000601)资助.

摘　　要：氮化碳材料固有的导电性差、电子迁移率低等问题导致高光生电荷复合率,阻碍了其光生电荷存储性能的提高.为此,构建了TiO_(2)富碳氮化碳共轭聚合物(CPCN)界面异质结,以提高光生电荷分离率.采用具有高比表面积(220.03 m^(2)/g)的TiO_(2)纳米晶介孔薄膜作为电子传输物质,通过增大TiO_(2)与CPCN之间的界面面积提高了电极反应活性,促进了光生空穴的高效抽取,获得了197 C/g的光生电荷存储容量.The light-induced accumulation of long-lived trapped electrons within the conjugated heptazine backbone enables polymeric carbon nitrides the dual ability of light absorption and charge storage.However,the photocharge storage capacity of C-rich polymeric carbon nitride(CPCN)has still been plagued by the severe recombination of photogenerated electrons and holes,which causes by its poor conductivity and low electron mobility.Herein,in order to enhance the photocharge separation,TiO_(2)was used to build an interfacial heterojunction with CPCN.Serving as the electron transporter,the used TiO_(2)nanocrystalline mesoporous film has high specific surface area of 220.03 m^(2)/g.The electrode reaction activity is significantly improved by increasing the interface area between TiO_(2)and CPCN.Owing to the desirable hole-extraction route for the CPCN photo-rechargeable cell,a remarkable photo-charging capacity of 197 C/g is achieved.The photoelectrode is prepared by coating the CPCN material on top of TiO_(2)sintered on an fluorine-doped tin oxide(FTO)substrate.The counter electrode is a platinized FTO glass.The electrolyte,using I_(3)^(-)/I^(-)(LiI and I_(2))in the solution of acetonitrile with a hint of water as the redox shuttle,is injected into the gap between the photoelectrode and the counter electrode to fabricate the cell.The microstructure and morphology of the TiO_(2)and CPCN materials are characterized by field emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM),X-ray diffraction(XRD),Fourier infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS)and nuclear magnetic resonance spectroscopy(NMR).The photoelectric and electrochemical properties of the TiO_(2),the CPCN as well as the TiO_(2)/CPCN photoelectrodes are investigated using ultraviolet photoelectron spectroscopy(UPS),UV-Vis absorption spectrum,cyclic voltammetry(CV),galvanostatic charge-discharge(GCD)and electrochemical impedance spectroscopy(EIS).

关 键 词：富碳氮化碳 二氧化钛 太阳能电池 可光充电电极 聚合物半导体 

分 类 号：O646[理学—物理化学]