g-C3N4 上氧化诱导的氮空位促进高选择性光催化 CO2 还原和析氢,Journal of Colloid and Interface Science

当前位置： X-MOL 学术 › J. Colloid Interface Sci. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

g-C3N4 上氧化诱导的氮空位促进高选择性光催化 CO2 还原和析氢
Journal of Colloid and Interface Science ( IF 9.4 ) Pub Date : 2023-08-05 , DOI: 10.1016/j.jcis.2023.08.012
Zhengdong Xu ₁ , Yang Chen ₂ , Binghao Wang ₁ , Yu Ran ₂ , Junbo Zhong ₂ , Minjiao Li ₁

Affiliation

在聚合氮化碳（PCN）中引入氮空位已被证明是增强光催化性能的可靠策略。氮空位被认为是活性位点，促进目标分子的吸附并捕获光生电子以抑制电荷对的复合，加速光生电子参与光催化反应。本文通过铬酸溶液刻蚀制备了一系列富含氮空位的PCN。样品20KCSCN具有最高的光催化性能，CO转化为CO和CH的效率分别达到3.9和0.5 μmol·g·h。这些演化效率比PCN高2.9倍和4倍。同时，20KCSCN表现出较高的CO转化选择性和稳定性。氮空位的成功引入不仅增加了PCN表面的活性位点，而且优化了光学结构，极大地提高了光生电荷对的分离和光生电子的还原能力。提出了PCN光催化CO还原性能的增强机制。此外，对所有样品进行了光催化析氢实验，以证实铬酸溶液蚀刻PCN光催化活性增强的普遍性。在300 W Xe灯下照射4 h后，20KCSCN的析氢速率可达652 μmol·g·h，是PCN（254 μmol·g·h）的1.6倍。这项工作为在 PCN 中引入氮空位来调节光激发电荷对转移提供了新的途径。光催化增强二氧化碳减排可用于缓解二氧化碳过量排放和能源危机的严重问题。

"点击查看英文标题和摘要"

Highly selective photocatalytic CO2 reduction and hydrogen evolution facilitated by oxidation induced nitrogen vacancies on g-C3N4

The introduction of nitrogen vacancies into polymeric carbon nitride (PCN) has been attested to be a reliable strategy to enhance photocatalytic performance. Nitrogen vacancies were considered as active sites to promote the adsorption of target molecules and capture photoexcited electrons to inhibit the recombination of charge pairs, accelerate photoinduced electrons to participate in photocatalytic reaction. In this paper, a series of PCN with rich nitrogen vacancies were prepared by etching of chromic acid solution. Sample 20KCSCN had the highest photocatalytic performance whose evolution efficiency of CO to CO and CH can reach 3.9 and 0.5 μmol·g·h, respectively. These evolution efficiencies are 2.9 and 4 times higher than that of the PCN. Meanwhile, 20KCSCN demonstrates high CO conversion selectivity and stability. The successful introduction of nitrogen vacancies not only increases the active sites of PCN surface, but also optimizes the optical structure, which dramatically boosts the separation of photoexcited charge pairs and the reduction capacity of photogenerated electrons. The enhancement mechanism for photocatalytic CO reduction performance of PCN was proposed. Besides, photocatalytic H evolution experiments were performed on all samples to confirm the universality of PCN photocatalytic activity enhancement etched by chromic acid solution. H evolution rate on 20KCSCN can reach 652 μmol·g·h, which is 1.6-fold higher than that on PCN (254 μmol·g·h) after 4 h irradiation under a 300 W Xe lamp. This work offers new venue for introducing nitrogen vacancies in PCN to regulate photoexcited charge pairs transfer. The photocatalytic enhancement of CO reduction could be used to alleviate the serious issue of excessive CO emission and energy crisis.

更新日期：2023-08-05

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南

全部期刊列表>>