Rahman Ashmalina, Khan Fazlurrahman, Jennings James Robert, Kim Young-Mog, Khan Mohammad Mansoob
Chemical Sciences, Faculty of Science, Universiti Brunei Darussalam, Jalan Tungku Link, Gadong, BE 1410, Brunei Darussalam.
Institute of Fisheries Science, Pukyong National University, Busan, 48513, Republic of Korea.
Sci Rep. 2024 Jul 12;14(1):16155. doi: 10.1038/s41598-024-66100-2.
Copper indium sulfide (CuInS) exhibits strong visible light absorption and thus has the potential for good photocatalytic activity; however, rapid charge recombination limits its practical usage. An intriguing strategy to overcome this issue is to couple CuInS with another semiconductor to form a heterojunction, which can improve the charge carrier separation and, hence, enhance the photocatalytic activity. In this study, photocatalysts comprising CuInS with a secondary CuS phase (termed CuInS) and CuInS loaded with ZnS (termed ZnS@CuInS) were synthesized via a microwave-assisted method. Structural and morphological characterization revealed that the ZnS@CuInS photocatalyst comprised tetragonal CuInS containing a secondary phase of hexagonal CuS, coupled with hexagonal ZnS. The effective band gap energy of CuInS was widened from 2.23 to 2.71 as the ZnS loading increased from 0 to 30%. The coupling of CuInS with ZnS leads to long-lived charge carriers and efficient visible-light harvesting properties, which in turn lead to a remarkably high activity for the photocatalytic degradation of brilliant green (95.6% in 5 h) and conversion of 4-nitrophenol to 4-nitrophenolate ions (95.4% in 5 h). The active species involved in these photocatalytic processes were evaluated using suitable trapping agents. Based on the obtained results, photocatalytic mechanisms are proposed that emphasize the importance of h, O, and OH in photocatalytic processes using ZnS@CuInS.
硫化铜铟（CuInS）具有很强的可见光吸收能力，因此具有良好的光催化活性潜力；然而，快速的电荷复合限制了其实际应用。克服这一问题的一个有趣策略是将CuInS与另一种半导体耦合形成异质结，这可以改善电荷载流子的分离，从而提高光催化活性。在本研究中，通过微波辅助法合成了含有次级CuS相的CuInS光催化剂（称为CuInS）和负载ZnS的CuInS光催化剂（称为ZnS@CuInS）。结构和形态表征表明，ZnS@CuInS光催化剂由含有六方CuS次级相的四方CuInS与六方ZnS耦合而成。随着ZnS负载量从0增加到30%，CuInS的有效带隙能量从2.23拓宽到2.71。CuInS与ZnS的耦合导致了长寿命的电荷载流子和高效的可见光捕获性能，进而导致对亮绿的光催化降解具有非常高的活性（5小时内降解率为95.6%）以及将4-硝基苯酚转化为4-硝基酚盐离子的活性（5小时内转化率为95.4%）。使用合适的捕获剂评估了这些光催化过程中涉及的活性物种。基于所得结果，提出了光催化机理，强调了h、O和OH在使用ZnS@CuInS的光催化过程中的重要性。
