近日，复旦大学张立武团队报道了水微滴上的强电场使H₂O₂光合作用的选择性接近统一。2025年9月24日出版的《美国化学会志》发表了这项成果。

在人工光合作用中，将太阳能选择性地转化为化学键仍然是一个巨大的挑战。虽然通过光催化双电子氧还原（2e^--ORR）生产H₂O₂为能源密集型的蒽醌工艺提供了一种可持续的替代方案，但竞争性的析氢反应（HER）严重限制了效率和选择性。

研究组发现水微滴表面的强电场作为强大的选择性开关，将光生电子完全导向H₂O₂合成，同时完全抑制氢的析出。这种界面电场控制机制将基于ZnIn₂S₄的光催化剂（通常以HER为主）转化为H₂O₂生产者，其选择性接近一致，生产速率比本体反应高2个数量级。通过空间分辨光谱表征和理论计算，研究组阐明了水微滴上的高电场同时增强了载流子分离，降低了2e^--ORR的能量势垒，并建立了对HER的动力学势垒。除了提供选择性H₂O₂光合作用的节能途径外，该研究还为其他太阳能到化学转化的选择性控制提供了有价值的见解，而无需催化剂修饰或系统工程。

附：英文原文

Title: Strong Electric Fields on Water Microdroplets Enable Near-Unity Selectivity in H2O2 Photosynthesis

Author: Kejian Li, Wenbo You, Yucheng Zhu, Wei Wang, Longqian Wang, Yangyang Liu, Qiuyue Ge, Tao Wang, Runbo Wang, Xuejun Ruan, Hanyun Cheng, Liwu Zhang

Issue&Volume: September 24, 2025

Abstract: Selective conversion of solar energy to chemical bonds remains a grand challenge in artificial photosynthesis. Though H2O2 production via photocatalytic two-electron oxygen reduction (2e–-ORR) offers a sustainable alternative to the energy-intensive anthraquinone process, competing hydrogen evolution reaction (HER) severely limits both efficiency and selectivity. Here, we reveal that the strong electric fields on water microdroplet surfaces serve as powerful selectivity switches, directing photogenerated electrons exclusively toward H2O2 synthesis while completely suppressing hydrogen evolution. This interfacial electric field control mechanism transforms ZnIn2S4-based photocatalysts─commonly dominated by HER─into H2O2 producers with near-unity selectivity and production rates 2 orders of magnitude higher than bulk reactions. Through spatially resolved spectroscopy characterizations and theoretical calculations, we elucidate that the high electric fields on water microdroplets simultaneously enhance charge carrier separation, lower energy barriers for 2e–-ORR, and erect kinetic barriers against HER. Beyond providing an energy-efficient route to selective H2O2 photosynthesis, this study offers valuable insights into selectivity control in other solar-to-chemical transformations without the need for catalyst modification or system engineering.

DOI: 10.1021/jacs.5c06077

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.5c06077