摘要
本研究以尿素为原料,采用热氧化剥离的方法制备g-C_(3)N_(4)纳米片,然后通过溶剂热和低温磷化两个过程原位制备了Co_(2)P/g-C_(3)N_(4)复合光催化剂。通过XRD、SEM、TEM、XPS等表征了催化剂的物相结构、形貌、元素组成及价态。结果表明,Co_(2)P纳米棒与g-C_(3)N_(4)纳米片组成的1D/2D组装结构的复合光催化剂被成功制备,且两者之间接触良好形成了紧密的异质结。光催化析氢性能测试结果表明,在可见光(λ>420 nm)下,5%Co_(2)P/g-C_(3)N_(4)(质量分数,下同)复合光催化剂的产氢速率达1155μmol·h^(-1)·g^(-1),是母体g-C_(3)N_(4)的96.3倍,且在循环测试中表现出良好的稳定性。通过UV-Vis漫反射光谱、光致发光光谱、瞬态光电流响应曲线和电化学阻抗谱图表征发现,与母体g-C_(3)N_(4)紧密接触的Co_(2)P可以拓宽其光响应范围,还能显著促进界面电荷的迁移,抑制光生电子-空穴对的复合,从而大幅提高g-C_(3)N_(4)的光催化析氢活性。
In this paper,using urea as raw material,g-C_(3)N_(4)nanosheets were prepared by thermal oxidation stripping method,and then Co_(2)P/g-C_(3)N_(4)composite photocatalysts were prepared in situ by solvothermal and low temperature phosphating processes.The phase structure,morphology and valence state composition of the catalyst were characterized by XRD,SEM,TEM and XPS.The results indicated that a compact 1D/2D heterojunction was formed between Co_(2)P nanorods and g-C_(3)N_(4)nanosheets.The results of hydrogen evolution test showed that the hydrogen production rate of 5%Co_(2)P/g-C_(3)N_(4)composite photocatalyst was up to 1155μmol·h^(-1)·g^(-1)under visible light irradiation(λ>420 nm),which was 96.3 times that of pure g-C_(3)N_(4),and it also showed a high stability in cycle test.Through UV-Vis diffuse reflectance spectra,photoluminescence spectra,transient photocurrent response curves and electrochemical impedance spectra characterization,it’s found that Co_(2)P closely contacted with the host g-C_(3)N_(4)could broaden its light response range,and significantly promoted the migration of interface charge,restrained the recombination of photogenerated electrons and holes,consequently significantly improved the g-C_(3)N_(4)photocatalytic activity of hydrogen evolution.
作者
向寒宾
苟浇浇
吴琳
曾春梅
XIANG Hanbin;GOU Jiaojiao;WU Lin;ZENG Chunmei(College of Chemistry and Chemical Engineering,China West Normal University,Nanchong 637002,Sichuan,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2022年第6期23-28,共6页
Materials Reports
基金
四川省教育厅重点项目(16ZA0176)
西华师范大学英才基金项目(17YC008)。
关键词
Co_(2)P
石墨相氮化碳
助催化剂
光催化析氢
Co_(2)P
graphite phase carbon nitride
cocatalyst
photocatalytic hydrogen evolution
