Photocatalytic selective oxidation under solvent-free conditions plays a pivotal role in green chemistry, which can diminish pollutant production and minimize resource consumption in chemical reactions. In this process, the activation of molecular oxygen (O) plays a crucial role. Here, we demonstrate the efficient oxidation of C(sp)–H bond in pure toluene to produce oxygenated products of benzaldehyde (BAD) and benzyl alcohol (BA) using O as an oxidant over lead-free MABiBr perovskite. Systematic spectroscopic characterizations and controlled experiments validate that MABiBr enables the activation of O to superoxide radical (•O) and singlet oxygen (O) via charged electron transfer and excitonic energy transfer, respectively. Significantly, O emerges as an important active species. The optimal photocatalytic performance delivered by MABiBr reaches a BAD generation rate of 10756 µmol gh, with a BAD product selectivity of 81.5 %. The performance is greater than most classical photocatalysts, representing one of the best photocatalytic activities available in the literature. The lead-free feature of MABiBr perovskite coupled with its impressive catalytic performance makes it promising for practical applications.

中文翻译：

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MA3Bi2Br9 钙钛矿光催化剂上通过高效单线态氧产生苯甲基 C(sp3)–H 键的无溶剂氧化


无溶剂条件下的光催化选择性氧化在绿色化学中发挥着关键作用，它可以减少化学反应中污染物的产生并最大限度地减少资源消耗。在此过程中，分子氧（O）的活化起着至关重要的作用。在这里，我们证明了使用 O 作为氧化剂，在无铅 MABiBr 钙钛矿上有效氧化纯甲苯中的 C(sp)-H 键，产生苯甲醛 (BAD) 和苯甲醇 (BA) 的氧化产物。系统光谱表征和对照实验证实，MABiBr 能够分别通过带电电子转移和激子能量转移将 O 活化为超氧自由基 (·O) 和单线态氧 (O)。值得注意的是，O 成为一种重要的活性物种。 MABiBr 提供的最佳光催化性能达到 10756 µmol gh 的 BAD 生成率，BAD 产物选​​择性为 81.5%。其性能优于大多数经典光催化剂，代表了文献中最好的光催化活性之一。 MABiBr 钙钛矿的无铅特性及其令人印象深刻的催化性能使其在实际应用中具有广阔的前景。