Bhunia Soumyadip, Mukherjee Manish, Purkayastha Pradipta
Department of Chemical Sciences and Center for Advanced Functional Materials, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, WB, India.
Langmuir. 2021 Mar 23;37(11):3500-3507. doi: 10.1021/acs.langmuir.1c00324. Epub 2021 Mar 10.
The perennial problem of instability of fluorescent copper nanoclusters (Cu NCs), stemming principally from aerial oxidation, has prevented their vivid usage in energy harvesting compared to the other metal NCs. However, replacement of the much expensive metal NCs with the cheaper Cu NCs is desirable if the functions are met with. Although thiolate protection of Cu NCs could bring some stability to them, appreciably decentlystable Cu NCs were produced inside the aqueous core of reverse micelles (RMs). However, this recent development has not been further explored on the photosensitization of the Cu NCs inside the RMs and their controlled modulation as energy antenna. Here we have synthesized stable Cu NCs inside the aqueous core of RMs with three different pool sizes and established photoinduced electron transfer (PET) to an electron acceptor. Considering the bulk quencher concentration, it appears that the extent of PET increases with decrease in the size of the aqueous core of RMs. However, calculating the effective concentration of the electron acceptor inside the RMs and considering the polarity of the microheterogeneous systems, it becomes clear that the extent of PET actually decreases with decrease in the size of the aqueous pool (, i.e., [HO]/[AOT]) = 5-20) in the RMs. This proof of concept and the results are promising toward applications in PET-driven phenomena such as solar cells or batteries.
荧光铜纳米团簇（Cu NCs）长期存在的稳定性问题主要源于空气氧化，这使得它们在能量收集方面与其他金属纳米团簇相比难以得到广泛应用。然而，如果能满足功能需求，用更便宜的Cu NCs替代昂贵的金属纳米团簇是很有必要的。虽然硫醇盐对Cu NCs的保护能使其具有一定稳定性，但在反胶束（RMs）的水核内可制备出相当稳定的Cu NCs。然而，这一最新进展尚未在RMs内Cu NCs的光敏化及其作为能量天线的可控调制方面得到进一步探索。在此，我们在具有三种不同水池尺寸的RMs水核内合成了稳定的Cu NCs，并实现了向电子受体的光致电子转移（PET）。考虑到本体猝灭剂浓度，PET的程度似乎随着RMs水核尺寸的减小而增加。然而，计算RMs内电子受体的有效浓度并考虑微非均相体系的极性后，很明显PET的程度实际上随着RMs水池尺寸（即[HO]/[AOT] = 5 - 20）的减小而降低。这一概念验证及结果对于在PET驱动的现象（如太阳能电池或电池）中的应用很有前景。
