【摘要】 本研究采用原位自牺牲法合成了N空位掺杂的g-C₃N₄/Cu₂（OH）₂CO₃（VCN/Cu）异质结催化剂，该催化剂体现出优异的可见-近红外宽光谱驱动性。实验结果表明，g-C₃N₄与Cu₂（OH）₂CO₃之间的电荷迁移遵循“Z”型机制。氮空位的存在抑制了电荷载流子的重组，降低了界面电荷转移的能量屏障，对N₂和O₂的吸附和活化激发了固氮还原反应的进行，并提供了更多的反应活性位点。体系中甲醇作为空穴清除剂时O₂的添加对制备的催化剂的光固氮性能有显著的促进作用，在50%O₂和50%N₂混合气氛下VCN/Cu异质结催化剂的铵离子产率高达14.52 mg·L^-1·h^-1·g^-1,是纯N₂气氛下的2.7倍，且按照“三线”光固氮机理运行。本研究为低耗、绿色环保固氮工艺提供了一条新途径。更多还原

【Abstract】 In this study, N vacancies-doped g-C₃N₄/Cu₂（OH）₂CO₃（VCN/Cu） heterojunction catalyst with superior wide-spectrum-driven（from VIS to NIR） N₂ photofixation ability was synthesized via in-situ self-sacrificial method.The experimental results show that the charge transfer between g-C₃N₄ and Cu₂（OH）₂CO₃ follows the ‘Z-scheme’ mechanism.N vacancies-induced defect states might act as the initial charge carriers acceptor to reduce electron/hole recombination, and also promote the interfacial charge transfer from N vacancies of excited g-C₃N₄ to N₂ and O₂molecules absorbed and pre-activated by N vacancies, leading more active sites.The nitrogen photofixation performance of as-prepared catalyst is deeply influenced by the O₂content in reaction system with methanol as hole scavenger.The as-prepared VCN/Cu heterojunction catalyst demonstrates the ammonium ion production rate as high as 14.52 mg·L^-1·h^-1·g^-1under the atmosphere of 50% O₂ and 50% N₂,which is 2.7 times higher than that under pure nitrogen atmosphere, and a ‘three-channel’ ammonia production mechanism is proposed.This study might open up a new vista to nitrogen fixation through the less energy-demanding green photocatalytic process.更多还原