硫取代氮增强g-C3N4光催化产氢性能
S-Doping of the N-Sites of g-C3N4 to Enhance Photocatalytic H2 Evolution Activity
王海涛 1余良浪 1江吉周 1Arramel 2邹菁1
作者信息
- 1. 武汉工程大学,化学与环境工程学院,环境生态与生物工程学院,绿色化工程教育部重点实验室,磷资源开发利用教育部工程研究中心,新型催化材料湖北省工程研究中心,武汉 430205
- 2. Nano Center Indonesia,Jalan Raya PUSPIPTEK,South Tangerang,Banten 15314,Indonesia
- 折叠
摘要
利用取之不尽的太阳能资源进行光催化水裂解制氢是缓解全球能源危机、实现碳中和战略的一项有前景的技术.石墨相氮化碳(g-C3N4)因成本低且稳定性高在光催化产氢领域备受关注.然而,纯g-C3N4存在表面积小、电子转移慢、光生载流子复合快等缺陷,产氢性能通常不佳.本研究通过直接热解硫酸铵和三聚氰胺混合物,成功实现硫物种对g-C3N4氮位点的原位取代,开发出一种高效的硫掺杂g-C3N4(S-g-CN)光催化剂.系列结构和光谱表征证实硫的成功掺杂.密度泛函理论的第一性原理计算表明S活性位对氢的吸附吉布斯自由能近乎为零(～0.26 eV),揭示S掺杂在优化H活性中间体吸附和解吸过程中起着重要作用.透射电子显微镜和原子力显微镜测试结果表明,S-g-CN具有超薄的纳米片状结构,其片层厚度约为2.5 nm.随后的氮气吸脱附等温线和光电化学性质测试结果表明,S掺杂不仅可显著增大g-C3N4比表面积,而且还能有效提高其光生电子-空穴对的转移、分离和氧化还原能力.得益于材料良好的结构特性,S-g-CN的光催化产氢速率高达4923 μmol∙g-1∙h-1,是原始g-C3N4的28倍,超越诸多最近报道的其它S掺杂g-C3N4光催化剂.而且,S-g-CN的表观量子效率高达3.64%.本研究除了开发一种高效的光催化剂,还将为高性能g-C3N4基催化剂的设计提供有益借鉴.
Abstract
The use of solar energy as an inexhaustible resource to conduct photocatalytic water splitting in hydrogen(H2)production can alleviate the worldwide energy crisis and achieve carbon neutrality.However,research in photocatalytic H2 evolution reaction(HER)is extremely challenging in terms of exploring the current development of an active and durable graphitic carbon nitride(g-C3N4)-based photocatalyst.Several parameters of pristine g-C3N4 require structural,physical,and chemical improvements,such as optimization of the surface area,electron transfer,and photo-generated carrier recombination,to render the g-C3N4 suitable for photocatalysis.In this study,the development of an efficient and robust S-doped g-C3N4(S-g-CN)catalyst was pursued that involves doping nitrogen(N)active sites of g-C3N4 with sulfur(S)dopants via one-step calcination of the sulphate and melamine precursors.A combination of structural and spectroscopic fingerprints was established to distinctly determine the realization of S-doping onto the g-C3N4 structure.We obtained the optimum Gibbs free energy of adsorbed hydrogen(ΔGH*)for S-g-CN at the S active sites,which is nearly zero(～0.26 eV),suggesting that the filled S dopants play an essential role in optimizing the adsorption and desorption processes of H-active intermediates.The results of atomic force and transmission electron microscopies(AFM and TEM)demonstrated that the produced S-g-CN catalyst has an ultrathin nanosheet structure with a lamellar thickness of approximately 2.5 nm.A subsequent N2 sorption isotherms test revealed a substantial increase in the specific surface area after the integration of S dopants into the g-C3N4 nanoskeleton.Moreover,the incorporation of S atoms into the g-C3N4 significantly increased the carrier concentrations,improving the transfer,separation,as well as the oxidation and reduction abilities of the photo-generated electron-hole pairs.Leveraging the favorable material characteristics of the S-doped two-dimensional nanostructures,the resulting S-g-CN achieved a high H2 evolution rate of 4923 μmol·g-1·h-1,which is 28 times higher than that of the pristine g-C3N4.Additionally,the developed S-g-CN possessed a high apparent quantum efficiency(3.64%)at visible-light irradiation.When compared to the recently reported S-doped g-C3N4-based photocatalysts,our optimal S-g-CN catalyst(S-CN1.0)showed one of the best HER catalytic activities.Our rational design is based on an effective strategy that not only explored a promising HER photocatalyst but also aimed to pave the way for the development of other high-performance g-C3N4 based catalysts.
关键词
理论预测/硫掺杂/g-C3N4/产氢/光催化Key words
Theoretical prediction/S-doping/g-C3N4/Hydrogen evolution/Photocatalysis引用本文复制引用
基金项目
国家自然科学基金(62004143)
湖北省重点研发计划(2022BAA084)
湖北省自然科学基金(2021CFB133)
国家重点研发计划(2022YFC3902703)
磷资源开发利用教育部工程研究中心创新项目(LCX2021003)
能量转换与存储材料化学教育部重点实验室开放基金(2021JYBKF05)
出版年
2024
国家科技期刊平台
NSTL
万方数据