氮化碳纳米片光电催化性能及界面反应机制  

Photoelectrocatalytic properties and interfacial reaction mechanism of carbon nitride nanosheets

作　　者：廖先龙 马晓清 LIAO Xianlong;MA Xiaoqing(School of Materials Science and Engineering,Shanghai University of Engineering Science,Shanghai 201620,China)

机构地区：[1]上海工程技术大学材料科学与工程学院,上海201620

出　　处：《功能材料》2023年第8期8025-8034,共10页Journal of Functional Materials

基　　金：国家自然科学基金项目(52002241)。

摘　　要：石墨相氮化碳(g-C_(3)N_(4))由于低成本、易制备、高化学和热稳定性、合适的带隙等优点受到广泛关注。然而,传统热聚合法制备的g-C_(3)N_(4)片层结构不明显,具有比表面积小、易团聚和光催化活性低等缺点。以热氧化法制备得到氮化碳纳米片为模型,进行光电催化性能测试。探究了外加偏压对光电流方向的影响,并对光电诱导下的电极界面反应机制进行了讨论。分别通过X射线衍射(XRD)、电子显微镜(SEM/HRTEM)、X射线光电子能谱(XPS)、光致发光光谱(PL)和紫外-可见漫反射吸收光谱(UV-Vis DRS)表征了样品的结构、形貌、和光学特性。系统研究了在空气气氛下热氧化法对氮化碳结构和光电化学性能的影响。BET比表面积分析得到,经过热氧化法剥离的氮化碳纳米片的比表面积(160.6 m^(2)/g)较块状g-C_(3)N_(4)(12.5 m^(2)/g)提升了1个数量级。此外,二维纳米片结构的g-C_(3)N_(4)在紫外可见光照射下的光电流密度相较于块状g-C_(3)N_(4)提高了一倍,析氧过电位明显降低。Graphite carbon nitride(g-C_(3)N_(4))has attracted wide attention due to its advantages of low cost,easy preparation,high chemical and thermal stability,and suitable band gap.However,g-C_(3)N_(4) prepared by traditional thermal polymerization method has the disadvantages of small surface area,easy aggregation and low photocatalytic activity.In this paper,carbon nitride nanosheets were prepared by a simple thermal oxidation method and tested through photoelectrochemical measurements.The effect of external bias on the direction of photocurrent was investigated by photochemical tests,and the reaction mechanism of electrode interface under photoelectric induction was discussed.The structure,morphology and optical properties of the samples were characterized by X-ray diffractometer(XRD),electron microscopy(SEM/HRTEM),X-ray photoelectron spectroscopy(XPS),photoluminescence spectroscopy(PL)and UV-Vis DRS.The effect of thermal oxidation on the structure and photoelectrochemical performance of carbon nitride in air atmosphere was systematically studied.The BET results showed that the specific surface area of the carbon nitride nanosheets(160.6 m^(2)/g)was one order of magnitude higher than that of the bulk g-C_(3)N_(4)(12.5 m^(2)/g).In addition,the photocurrent density of g-C_(3)N_(4) with two-dimensional nanosheet structure is twice as high as that of the bulk g-C_(3)N_(4) under UV-vis light,and a lower OER potential was obtained.

关 键 词：氮化碳 纳米片 热氧化法 能带弯曲 光电响应 

分 类 号：TB332[一般工业技术—材料科学与工程]