One-step construction of S-scheme heterojunctions of N-doped MoS2 and S-doped g-C3N4 for enhanced photocatalytic hydrogen evolution
One-step construction of S-scheme heterojunctions of N-doped MoS2 and S-doped g-C3N4 for enhanced photocatalytic hydrogen evolution
复制标题
N掺杂MoS2和S掺杂g-C3N4的S型异质结的一步构建用于增强光催化析氢
DOI：
10.1016/j.cej.2020.126498
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发表时间：
2021-01-15
影响因子：
15.1
通讯作者：
Ye, Liqun
中科院分区：
文献类型：
--
作者：
Chen, Yanli;Su, Fengyun;Ye, Liqun
以硫脲和四硫代钼酸铵为起始原料，在Ar气氛下通过一步热缩聚法构建了S掺杂的g-C3N4（SCN）和N掺杂的MoS2（NMS）的阶梯式（S型）异质结。 X射线光电子能谱揭示了SCN和NMS之间新的N-Mo和C-SMo键的形成，并提高了NMS的纯度。所制备的 NMS/SCN 的 NMS 比例为 19.3 wt%，显示出最高的光催化活性。在光照4 h内，其产氢率达到658.5 μmol/g/h，分别比纯SCN（28.8 μmol/g/h）和NMS（17.4 μmol/g/h）高约23和38倍。紫外可见漫反射光谱（DRS）、表面光电压光谱（SPV）、光致发光（PL）光谱和电化学测试表明所形成的S型异质结具有扩展的可见光吸收和增强的光生载流子分离。研究并讨论了S型异质结光催化剂中电荷转移和分离的机理和驱动力。
Step-scheme (S-scheme) heterojunctions of S-doped g-C3N4 (SCN) and N-doped MoS2 (NMS) were constructed by a one-step thermal polycondensation method in Ar atmosphere using thiourea and ammonium tetrathiomolybdate as starting materials. X-ray photoelectron spectra revealed the formation of new N-Mo and C-SMo bonds between SCN and NMS and enhanced NMS purity. The as-prepared NMS/SCN with an NMS ratio of 19.3 wt% showed the highest photocatalytic activity. Within 4 h of illumination, its H2 generation rate reached 658.5 mu mol/g/h, which was about 23 and 38 times higher than that of pure SCN (28.8 mu mol/g/h) and NMS (17.4 mu mol/g/h), respectively. UV-vis diffuse reflectance spectra (DRS), surface photovoltage spectrum (SPV), photoluminescence (PL) spectra and electrochemical tests revealed the extended visible light absorption and enhanced photo-generated carrier separation of the formed S-scheme heterojunction. The mechanism and driving force of charge transfer and separation in S-scheme heterojunction photocatalysts are investigated and discussed.