Wang Jingyuan, Luo Xuan
National Graphene Research and Development Center, Springfield, Virginia 22151, United States.
ACS Omega. 2024 Jan 5;9(3):3772-3780. doi: 10.1021/acsomega.3c07795. eCollection 2024 Jan 23.
In recent years, carbon capture and utilization (CCU) has been explored as an attractive solution to global warming, which is mainly caused by increasing CO emission levels. Many functional materials have been developed for removing atmospheric CO and converting it to more useful forms of carbon. Traditional metallic photocatalytic species have drawbacks-photocorrosion, low visible-light absorbance, and environmental damage; therefore, metal-free materials have attracted considerable research attention. In particular, boron nitride (BN) possesses unique B-N bonds, characterized by a large difference in the electronegativity of atoms that facilitates CO reduction, and catalytic CO reduction by boron carbon nitride (BCN) has been demonstrated under visible light; hence, these two materials can be considered potential CO reduction photocatalysts. However, further modification of the materials and their applicability to other CCU applications have not been extensively explored. Therefore, we decided to investigate the modification of BCN monolayers, with the aim of ensuring that the properties of the materials are better suited, first, to the requirements of CO photocatalysis, and second, to those of carbon capture or other optoelectronic applications. In this study, we considered various novel BCN monolayers, based on modification via metal-free substitutional doping and nitrogen vacancy creation, and performed first-principles density functional theory calculations. The effects of the modifications on band gap tuning, charge transfer, and the CO adsorption ability were all studied. Specifically, O-BCN and Si-2 × 2-BCN were shown to possess excellent properties for photocatalytic CO reduction, and O-2 × 2-BCN and N-4 × 4-BN can be considered for future CO capture materials. These results contribute to existing CCU approaches, suggesting that BCN monolayer modification merits further investigation, and offering insights relevant to other photocatalytic applications.
近年来，碳捕获与利用（CCU）作为一种应对全球变暖的极具吸引力的解决方案受到了探索，全球变暖主要是由二氧化碳排放水平上升导致的。人们已开发出许多功能材料用于去除大气中的二氧化碳并将其转化为更有用的碳形式。传统的金属光催化物种存在光腐蚀、可见光吸收率低和环境破坏等缺点；因此，无金属材料引起了相当多的研究关注。特别是，氮化硼（BN）具有独特的B-N键，其特征是原子电负性差异大，这有利于二氧化碳还原，并且已证明在可见光下硼碳氮化物（BCN）可催化二氧化碳还原；因此，这两种材料可被视为潜在的二氧化碳还原光催化剂。然而，材料的进一步改性及其在其他CCU应用中的适用性尚未得到广泛探索。因此，我们决定研究BCN单层的改性，目的是确保材料的性能首先更适合二氧化碳光催化的要求，其次更适合碳捕获或其他光电应用的要求。在本研究中，我们基于无金属替代掺杂和氮空位形成的改性方法考虑了各种新型BCN单层，并进行了第一性原理密度泛函理论计算。研究了改性对带隙调节、电荷转移和二氧化碳吸附能力的影响。具体而言，O-BCN和Si-2×2-BCN表现出优异的光催化二氧化碳还原性能，O-2×2-BCN和N-4×4-BN可被视为未来的二氧化碳捕获材料。这些结果为现有的CCU方法做出了贡献，表明BCN单层改性值得进一步研究，并为其他光催化应用提供了相关见解。
