Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education, Jilin Normal University, Changchun, Jilin 130103, China; MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150001, China.
Key Laboratory of Marine Environmental Corrosion and Bio-fouling, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, Shandong 266071, China.
J Colloid Interface Sci. 2022 Aug 15;620:313-321. doi: 10.1016/j.jcis.2022.04.015. Epub 2022 Apr 8.
Two-dimensional (2D) layered double hydroxides (LDHs) and graphitic carbon nitride (g-CN) with sufficiently positive valence bands and negative conduction bands are promising materials for producing superoxide radicals (·O) and hydroxyl radicals (·OH) for photocatalytic sterilization; however, their relatively wide bandgaps limit the utilization of light in photocatalysis. Herein, the electronegative N-CN nanosheets were used to adsorb Cu, Zn and Al cations in situ to form uniformly distributed LDHs nanosheets. Then, the LDHs on LDHs/N-CN composites were partially reduced in situ into ultrafine CuO to harvest sufficient solar energy. Zeta potential measurements revealed that the constructed CuO/LDHs/N-CN composites and bacterial solution exhibited opposite charges, which induced strong electrostatic adsorption in photocatalytic sterilization. Under visible light, the highly hydrophilic 0D/2D/2D CuO/LDHs/N-CN heterojunctions exhibited the highest sterilization rate of 98.96% toward Escherichia coli without an obvious decrease after 4 cycles. It was experimentally and theoretically confirmed that a dual Z-scheme charge migration path in the CuO/LDHs/N-CN heterojunction was achieved, harnessing the full synergetic potential of the combined system. This work provides an effective method for synthesizing a robust, hydrophilic and positively charged heterojunction to further improve photocatalytic sterilization activity.
二维（2D）层状双氢氧化物（LDHs）和石墨相氮化碳（g-CN）具有足够正的价带和负的导带，是用于光催化杀菌产生超氧自由基（·O）和羟基自由基（·OH）的有前途的材料；然而，它们相对较宽的带隙限制了光在光催化中的利用。在此，使用电负性的 N-CN 纳米片原位吸附 Cu、Zn 和 Al 阳离子，形成均匀分布的 LDHs 纳米片。然后，LDHs 在 LDHs/N-CN 复合材料上部分原位还原为超细的 CuO，以充分利用太阳能。Zeta 电位测量表明，构建的 CuO/LDHs/N-CN 复合材料和细菌溶液带相反电荷，这在光催化杀菌中诱导了强烈的静电吸附。在可见光下，高度亲水性的 0D/2D/2D CuO/LDHs/N-CN 异质结对大肠杆菌的杀菌率最高，达到 98.96%，经过 4 次循环后没有明显下降。实验和理论证实，在 CuO/LDHs/N-CN 异质结中实现了双 Z 型电荷迁移路径，利用了组合系统的全部协同潜力。这项工作为合成坚固、亲水和带正电的异质结提供了一种有效方法，以进一步提高光催化杀菌活性。
