Abstract：
Creating cross-linking to establish efficient inter-chain charge-transfer channels in carbon nitride represents a promising strategy for enhancing its photocatalytic capabilities. Molten salt-assisted calcining has emerged as a method for preparing cross-linked carbon nitrides. However, the precise influence of molten salts on the molecular structure of carbon nitride remains to be fully elucidated. Herein, we develop a KCl guided cross-linking reaction to preliminarily reveal the formation mechanism of cross-linking. The cross-linking reaction is initiated by the pre-coordination of amino groups with K+. Subsequent heating at high temperature converts the amino groups into chlorines. Then, dechlorination leads to the formation of cross-linking. Thus, this cross-linking reaction can be accurately described as a pre-coordination-induced, two-step deamination reaction. The pre-coordination step plays a pivotal role in the cross-linking process. Sufficient pre-coordination results in a relatively high cross-linking degree of the as-prepared CNK-2. Consequently, CNK-2 demonstrates a significantly enhanced photocatalytic H2O2 production, with a generation rate of 682 μmol·L-1·h-1, about 59 times that of traditional carbon nitride.
摘要：
创建交联以在氮化碳中建立有效的链间电荷转移通道代表了增强其光催化能力的有希望的策略。熔融盐辅助煅烧已成为制备交联碳氮化物的方法。然而,熔盐对氮化碳分子结构的精确影响仍有待充分阐明。在这里，我们开发了KCl引导的交联反应，初步揭示了交联的形成机理。通过氨基与K+的预配位引发交联反应。随后在高温下加热将氨基转化成氯。然后，脱氯导致交联的形成。因此，这种交联反应可以准确地描述为预配位诱导，两步脱氨反应。预配位步骤在交联过程中起关键作用。充分的预配位导致所制备的CNK-2的相对高的交联度。因此,CNK-2显示出显著提高的光催化H2O2生产，生成速率为682μmol·L-1·h-1，约为传统氮化碳的59倍。
