Homodispersed B-CN/P-CN S-scheme Homojunction for Enhanced Visible-light-driven Hydrogen Evolution
Homodispersed B-CN/P-CN S-scheme Homojunction for Enhanced Visible-light-driven Hydrogen Evolution
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用于增强可见光驱动析氢的均质分散 B-CN/P-CN S 型同质结
DOI：
10.1016/j.gee.2021.01.012
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发表时间：
--
影响因子：
13.3
通讯作者：
Guofeng Guan
中科院分区：
文献类型：
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作者：
Dashui Yuan;Zongyuan Li;Xueru Chen;Jing Ding;Hui Wan;Guofeng Guan
在光催化剂的光激发电荷分离中，合适的界面和带对准一直起着至关重要的作用。在这项工作中，我们通过简单的预掺杂和两步煅烧方法制备了具有局域电子结构差异的均匀分散的S-scheme氮化碳均结。硼掺杂到七嗪中产生了额外的受体杂质，磷掺杂到七嗪中产生了额外的给体杂质，最终改变了氮化碳的电子结构。不同元素掺杂的七嗪通过再煅烧整合到氮化碳中，B-CN和P-CN形成了均匀分散的同质结，从而产生了丰富的界面。同时，由于费米能级平衡引起的能带弯曲构造了s型同质结，刺激光生电子从B-CN的CB转移到P-CN的VB。均匀分散的S-scheme结构有效抑制了光诱导电荷的重组，保留了更强的氧化还原电荷。结果表明，在4 h的析氢过程中，纯CN的光催化性能从60 μmol g−1显著提高到2620 μmol g−1。这种新型的电子结构工程方法为设计具有优异光催化性能的均结光催化剂提供了新的思路。
Proper interface and band alignment always play essential roles in the separation of photoexcited charge of photocatalysts. In this work, we prepared a homodispersed S-scheme carbon nitride homojunction with local electron structure difference by a facile pre-doping and two-step calcination approach. Boron doping into heptazine created extra acceptor impurity, and phosphorus doping into heptazine created extra donor impurity, which eventually modulated the electronic structure of carbon nitride. As heptazines with different element doping were integrated into carbon nitride by recalcination, B–CN and P–CN formed a homodispersed homojunction and thus produced a rich interface. Meanwhile, caused by Fermi energy levels equilibrium, the band bending constructed an S-scheme homojunction, which stimulated photogenerated electrons to transfer from CB of B–CN to VB of P–CN. The homodispersed S-scheme homojunction structure led to efficient suppression of recombination of photoinduced charge and retained stronger redox charge. Consequently, the photocatalytic performance was dramatically boosted to 2620 μmol g−1from 60 μmol g−1of pure CN in 4-h hydrogen evolution from water. This novel method for electron structure engineering helped to provide a new strategy for designing homojunction photocatalysts with excellent photocatalytic performance.