原位构筑质子化氮化碳/碳化钛光催化制氢肖特基异质结

doi:10.1016/S1872-2067(20)63559-8

催化学报 ›› 2021, Vol. 42 ›› Issue (1): 107-114.DOI: 10.1016/S1872-2067(20)63559-8

原位构筑质子化氮化碳/碳化钛光催化制氢肖特基异质结

徐浩添^a, 肖蓉^a, 黄靖然^a, 姜燕^a^,^#(), 赵呈孝^b, 杨小飞^a^,^b^,^c^,^*()

^a江苏大学材料科学与工程学院, 江苏镇江212013
^b南京林业大学理学院材料物理与化学研究所, 江苏南京210037
^c哈尔滨师范大学光电带隙材料教育部重点实验室, 黑龙江哈尔滨150025

收稿日期:2020-02-28 接受日期:2020-04-18 出版日期:2021-01-18 发布日期:2020-01-15
通讯作者: 姜燕,杨小飞
基金资助:
国家自然科学基金(21975129);江苏省“六大人才高峰”高层次人才项目(2015-XCL-026);江苏省自然科学基金(BK20171299);南京林业大学引进高层次人才科研启动基金;福州大学能源与环境光催化国家重点实验室开放基金(SKLPEE-KF201705)

In situ construction of protonated g-C₃N₄/Ti₃C₂ MXene Schottky heterojunctions for efficient photocatalytic hydrogen production

Haotian Xu^a, Rong Xiao^a, Jingran Huang^a, Yan Jiang^a^,^#(), Chengxiao Zhao^b, Xiaofei Yang^a^,^b^,^c^,^*()

^aSchool of Materials Science & Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu, China
^bCollege of Science, Institute of Materials Physics and Chemistry, Nanjing Forestry University, Nanjing 210037, Jiangsu, China
^cKey Laboratory for Photonic and Electronic Bandgap Materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin 150025, Heilongjiang, China

Received:2020-02-28 Accepted:2020-04-18 Online:2021-01-18 Published:2020-01-15
Contact: Yan Jiang,Xiaofei Yang
About author:^#E-mail: jiangy@ujs.edu.cn
^*E-mail: xiaofei.yang@njfu.edu.cn;
Supported by:
National Natural Science Foundation of China(21975129);Six Talent Peaks Project in Jiangsu Province(2015-XCL-026);Natural Science Foundation of Jiangsu Province(BK20171299);Start-up Fund from Nanjing Forestry University;State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University(SKLPEE-KF201705)

摘要/Abstract

摘要：

氢气因其具有高燃烧热、可再生性以及燃烧产物无污染等优势被认为是一种绿色可再生能源, 是取代化石燃料的候选能源之一. 然而, 如何利用自然界中丰富的太阳能和水资源实现光分解水制氢的关键在于开发高效的光催化剂. 在尺寸明确、能级带隙匹配的纳米材料间进行完美的界面复合(异质结构筑)是实现高效太阳能-氢能转换的最佳途径. 石墨相氮化碳(CN)材料因其电子结构可调和化学性能稳定等特性被光催化界所关注. 然而, 氮化碳材料较弱的电学性能如电荷传输能力差及电子-空穴对复合率高导致其表现出较低的光催化制氢效率. 基于此, 我们用盐酸对氮化碳进行质子化处理, 使材料表面电荷发生改变, 从而实现氮化碳的电子带隙调节和电导率提升. 在此基础上, 将二维碳化钛原位负载于质子化的氮化碳(PCN)纳米片表面构筑肖特基结. PCN纳米片与碳化钛纳米片间的良好界面接触促进了电荷在材料界面上传输, 进而加速了氮化碳材料的电荷分离, 实现了氮化碳光催化剂活性的提升.
Zeta电位测试结果显示, CN和PCN的表面电位分别为-9.5和27.3 mV, 表明质子化处理可以有效改变材料表面电荷, 并促其与碳化钛纳米片进行静电组装. 该结果进一步得到了扫描电子显微镜(SEM)和原子力显微镜(AFM)的证实. 改变表面电荷使氮化碳材料的能带宽度由2.53 eV (CN)减小到2.41 eV (PCN), 增强了可见光区吸收. 同时, PCN的光电流密度提升了约4倍, 电子阻抗和激发态电子的辐射复合都显著降低. 将PCN与碳化钛复合制得复合材料(PCN-x, x = 10, 20, 40), 实验结果表明5 g的PDN最佳负载碳化钛的量为20 mg (PCN-20). 在标准太阳模拟器的可见光区(> 420 nm), 复合材料PCN-20的光催化水分解产氢量可达2181 μmol·g^-1, 是CN催化剂的约5.5倍, PCN的2.7倍, 并且经过5次产氢循环后PCN-20仍具有稳定的氢气释放速率. 以上结果表明, 氮化碳材料可以通过质子化处理以及与适量的碳化钛复合实现光催化产氢性能的提升, 其中碳化钛在体系中起助催化剂的作用. 该研究结果可为其他半导体光催化剂的性能优化以及非贵金属助催化剂的研究提供新思路.

关键词: 氮化碳, 碳化钛, 杂化, 肖特基异质结, 质子化, 光催化产氢

Abstract:

Abstract: Converting sustainable solar energy into hydrogen energy over semiconductor-based photocatalytic materials provides an alternative to fossil fuel consumption. However, efficient photocatalytic splitting of water to realize carbon-free hydrogen production remains a challenge. Heterojunction photocatalysts with well-defined dimensionality and perfectly matched interfaces are promising for achieving highly efficient solar-to-hydrogen conversion. Herein, we report the fabrication of a novel type of protonated graphitic carbon nitride (PCN)/Ti₃C₂MXene heterojunctions with strong interfacial interactions. As expected, the two-dimensional (2D) PCN/2D Ti₃C₂MXene interface heterojunction achieves a highly improved hydrogen evolution rate (2181 μmol∙g^-1) in comparison with bulk g-C₃N₄(393 μmol∙g^-1) and protonated g-C₃N₄ (816 μmol∙g^-1). The charge-regulated surfaces of PCN and the accelerated charge transport at the face-to-face 2D/2D Schottky heterojunction interface are the major contributors to the excellent hydrogen evolution performance of the composite photocatalyst.

Key words: g-C₃N₄, Ti₃C₂, Hybridization, Schottky heterojunction, Protonation, Photocatalytic hydrogen production

徐浩添, 肖蓉, 黄靖然, 姜燕, 赵呈孝, 杨小飞. 原位构筑质子化氮化碳/碳化钛光催化制氢肖特基异质结[J]. 催化学报, 2021, 42(1): 107-114.

Haotian Xu, Rong Xiao, Jingran Huang, Yan Jiang, Chengxiao Zhao, Xiaofei Yang. In situ construction of protonated g-C₃N₄/Ti₃C₂ MXene Schottky heterojunctions for efficient photocatalytic hydrogen production[J]. Chinese Journal of Catalysis, 2021, 42(1): 107-114.

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链接本文: https://www.cjcatal.com/CN/10.1016/S1872-2067(20)63559-8

https://www.cjcatal.com/CN/Y2021/V42/I1/107

图/表 9

Fig. 1. Synthesis flow chart for the PCN/MXene composites.

Fig. 2. SEM images of CN (a), PCN (b), and MXene nanosheets (c); SEM image and corresponding elemental mapping images of the composite PCN-20 (d, e).

Fig. 3. AFM images (a, b) and height cutaway view of MXene and PCN nanosheets (c, d).

Fig. 4. XRD patterns (a) and FT-IR spectra (b) of PCN-20, PCN, CN, and MXene.

Fig. 5. Hydrogen production (a) of CN, PCN, and PCN-x (x = 10, 20, 40); five hydrogen production cycles using the composite PCN-20 (b).

Fig. 6. UV-vis diffuse reflectance spectra of MXene, CN, PCN, and PCN-20 (a); Optical bandgaps of CN and PCN (b); Mott-Schottky plots of CN and PCN (c); Schematic illustration of the band structures of CN and PCN (d).

Fig. 7. (a) Transient photocurrent responses and (b) EIS Nyquist plots of CN, PCN, and PCN-20 in 1 mol·L-1 Na2SO4 aqueous solutions under visible light irradiation.

Fig. 8. Photoluminescence spectra (a) and photoluminescence decay curves of CN (b), PCN (c), and PCN-20 (d).

Fig. 9. Charge-transfer progress in the 2D/2D MXene/PCN system during photocatalytic H2 evolution under visible light.

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原位构筑质子化氮化碳/碳化钛光催化制氢肖特基异质结

In situ construction of protonated g-C₃N₄/Ti₃C₂ MXene Schottky heterojunctions for efficient photocatalytic hydrogen production

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原位构筑质子化氮化碳/碳化钛光催化制氢肖特基异质结

In situ construction of protonated g-C3N4/Ti3C2 MXene Schottky heterojunctions for efficient photocatalytic hydrogen production

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In situ construction of protonated g-C₃N₄/Ti₃C₂ MXene Schottky heterojunctions for efficient photocatalytic hydrogen production