International Journal of Hydrogen Energy ( IF 8.1 ) Pub Date : 2019-12-31 , DOI: 10.1016/j.ijhydene.2019.12.074
Zuju Ma , Zhitao Cui , Yaohui Lv , Rongjian Sa , Kechen Wu , Qiaohong Li
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The insufficient oxidation capacity, high carrier recombination rate and limited sunlight absorption seriously suppress the photocatalytic activity of pure g-C3N4. Using state-of-the-art hybrid density functional theory, we report an efficient method to tackle all aforementioned issues of g-C3N4 by metal-nonmetal (S and K) co-doping here. We find the adsorption of K atom on hollow site causes dynamic strain of g-C3N4. The S + K co-doping not only shifts the band edges downwards to achieve a much large overpotential of ca. 0.76 V, but also significantly extends the visible-light absorption threshold of g-C3N4. More importantly, the newly established channel between neighboring heptazine units in the doped structure is highly favorable for the separation of charge carriers. Our results help the design of high-performance visible-light-responsive g–C3N4–based photocatalyst for solar water splitting.
中文翻译:
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三合一:开放的电荷传输通道,正迁移的氧化电势,以及通过K和S共掺杂而增强的gC 3 N 4光催化剂的可见光响应
不足的氧化能力,高的载流子复合率和有限的日光吸收严重地抑制了纯gC 3 N 4的光催化活性。我们使用最新的混合密度泛函理论,在此报告了一种通过金属-非金属(S和K)共掺杂解决gC 3 N 4的所有上述问题的有效方法。我们发现K原子在空心位点上的吸附会引起gC 3 N 4的动态应变。S + K共掺杂不仅使能带边缘向下移动,从而使ca的超电势大大提高。0.76 V,但也显着延长了gC 3 N 4的可见光吸收阈值。更重要的是,在掺杂结构中相邻的庚嗪单元之间新建立的通道对于电荷载流子的分离是非常有利的。我们的结果有助于设计用于可见光分裂的高性能可见光响应式g–C 3 N 4基光催化剂。