Efficient spatial charge separation and transfer in ultrathin g-C3N4 nanosheets modified with Cu2MoS4 as a noble metal-free co-catalyst for superior visible light-driven photocatalytic water splitting
Efficient spatial charge separation and transfer in ultrathin g-C3N4 nanosheets modified with Cu2MoS4 as a noble metal-free co-catalyst for superior visible light-driven photocatalytic water splitting
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DOI：
10.1039/c8cy00898a
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发表时间：
2018-07
影响因子：
5
通讯作者：
Yajun Zou;Jian-Wen Shi;Dandan Ma;Zhaoyang Fan;Chi He;Linhao Cheng;Diankun Sun;Jun Li;Zeyan Wang;C. Niu
中科院分区：
文献类型：
--
作者：
Yajun Zou;Jian-Wen Shi;Dandan Ma;Zhaoyang Fan;Chi He;Linhao Cheng;Diankun Sun;Jun Li;Zeyan Wang;C. Niu
开发具有高效空间电荷分离和转移以及高光捕获能力的光催化剂仍然是一个关键挑战。在这里，我们报告了一种简单的原位工艺，用助催化剂 Cu2MoS4 装饰超薄 g-C3N4 纳米片 (NSs)，用于光催化水分解。所获得的Cu2MoS4/g-C3N4在可见光照射下表现出优异的光催化产氢速率，为2170.5 μmol h−1 g−1，分别比块状g-C3N4和g-C3N4 NSs高出近677倍和34倍，并且远远超过大多数用其他硫化物改性的g-C3N4催化剂。 文献报道的助催化剂表明，Cu2MoS4 可以作为一种有前景的非贵金属助催化剂，与 g-C3N4 偶联，形成高效光催化剂。结构表征证实了 Cu2MoS4/g-C3N4 的明确形貌，其中 Cu2MoS4 空心球均匀附着在具有大量微孔和空位的超薄 g-C3N4 NS 上。光学性质表明Cu2MoS4/g-C3N4具有极好的可见光吸收能力。光致发光光谱、光电流响应和电化学阻抗谱相结合，证明了光生电子和空穴的高效分离和迁移。所有这些因素协同增强了Cu2MoS4/g-C3N4光催化水分解的光催化活性，为合理设计基于地球丰富元素的高性能可见光驱动光催化剂提供了新的见解。
Developing photocatalysts with efficient spatial charge separation and transfer as well as a high light-harvesting ability remains a key challenge. Here, we report a facile in situ process to decorate ultrathin g-C3N4 nanosheets (NSs) with a co-catalyst, Cu2MoS4, for photocatalytic water splitting. The as-obtained Cu2MoS4/g-C3N4 exhibits a superior photocatalytic H2 evolution rate of 2170.5 μmol h−1 g−1 under visible light irradiation, which is nearly 677 and 34 times higher than that of bulk g-C3N4 and g-C3N4 NSs, respectively, and far exceeds that of most g-C3N4 catalysts modified with other sulphide co-catalysts reported in the literature, demonstrating that Cu2MoS4 can serve as a promising non-noble metal co-catalyst to couple with g-C3N4 for highly efficient photocatalysts. Structural characterization confirms the well-defined morphology of Cu2MoS4/g-C3N4 in which Cu2MoS4 hollow spheres are uniformly attached on the ultrathin g-C3N4 NSs with numerous micropores and vacancies. The optical properties indicate that Cu2MoS4/g-C3N4 possesses a superb visible light absorption ability. The photoluminescence spectra, photocurrent response, and electrochemical impedance spectra combine to prove the highly efficient separation and migration of photogenerated electrons and holes. All these factors synergistically enhance the photocatalytic activity of Cu2MoS4/g-C3N4 for photocatalytic water splitting, providing new insights into the rational design of high-performance visible light-driven photocatalysts based on earth-abundant elements.