Yang Zhimin, Wang Dongyang, Zhang Yun, Feng Zhenyu, Liu Luntao, Wang Wenshou
National Engineering Research Center for Colloidal Materials, School of Chemistry and Chemical Engineering , Shandong University , Jinan 250100 , P. R. China.
ACS Appl Mater Interfaces. 2020 Feb 19;12(7):8604-8613. doi: 10.1021/acsami.9b22447. Epub 2020 Feb 7.
The reversible photocatalytic color switching systems (PCSSs) driven by semiconductor nanoparticles have attracted considerable attention because of their wide applications. However, the developed semiconductor nanoparticles with photoreductive activity are mainly limited to TiO-based photocatalysts, which greatly hinder their broad applications. Here we report a cocapping ligand-assisted strategy for the development of photoreductive BiOCl ultrathin nanosheets with abundant oxygen vacancies. Both the cocapping ligands and oxygen vacancies in BiOCl ultrathin nanosheets act as sacrificial electron donors to efficiently scavenge the photogenerated holes, endowing the BiOCl ultrathin nanosheets high photoreductive activity and thus enabling the photocatalytic color switching of redox dyes, such as methylene blue (MB) and neutral red. By successfully integrating the BiOCl ultrathin nanosheet/MB/HO color switching system with poly(vinyl alcohol) hydrogel to fabricate a twistable gel film and simultaneously solving the dye-leaching issue of the gel film in a water environment, we further demonstrate its application in a colorimetric oxygen indicator for food packaging, exhibiting high sensitivity to monitor oxygen leakage by the naked eye. We believe the work opens a new avenue for designing photoreductive semiconductor nanomaterials to enrich the PCSSs and their applications.
由半导体纳米颗粒驱动的可逆光催化颜色切换系统（PCSSs）因其广泛的应用而备受关注。然而，已开发的具有光还原活性的半导体纳米颗粒主要局限于TiO基光催化剂，这极大地阻碍了它们的广泛应用。在此，我们报道了一种共封端配体辅助策略，用于开发具有丰富氧空位的光还原BiOCl超薄纳米片。BiOCl超薄纳米片中的共封端配体和氧空位均作为牺牲电子供体，有效地清除光生空穴，赋予BiOCl超薄纳米片高光还原活性，从而实现氧化还原染料（如亚甲基蓝（MB）和中性红）的光催化颜色切换。通过成功地将BiOCl超薄纳米片/MB/H₂O颜色切换系统与聚乙烯醇水凝胶集成，制备出可扭曲的凝胶膜，同时解决了凝胶膜在水环境中的染料渗漏问题，我们进一步展示了其在食品包装比色氧指示剂中的应用，对肉眼监测氧气泄漏表现出高灵敏度。我们相信这项工作为设计光还原半导体纳米材料开辟了一条新途径，以丰富PCSSs及其应用。
