The objective of photocatalytic CO₂ reduction (PCR) is to achieve high selectivity for a single energy-bearing product with high efficiency and stability. The bulk configuration usually determines charge carrier kinetics, whereas surface atomic arrangement defines the PCR thermodynamic pathway. Concurrent engineering of bulk and surface structures is therefore crucial for achieving the goal of PCR. Herein, an ultrastable and highly selective PCR using homogeneously doped BiOCl nanosheets synthesized via an inventive molten strategy is presented. With B₂O₃ as both the molten salt and doping precursor, this new doping approach ensures boron (B) doping from the surface into the bulk with dual functionalities. Bulk B doping mitigates strong excitonic effects confined in 2D BiOCl by significantly reducing exciton binding energies, whereas surface-doped B atoms reconstruct the BiOCl surface by extracting lattice hydroxyl groups, resulting in intimate B-oxygen vacancy (B-OV) associates. These exclusive B-OV associates enable spontaneous CO₂ activation, suppress competitive hydrogen evolution and promote the proton-coupled electron transfer step by stabilizing *COOH for selective CO generation. As a result, the homogeneous B-doped BiOCl nanosheets exhibit 98% selectivity for CO₂-to-CO reduction under visible light, with an impressive rate of 83.64 µmol g⁻¹ h⁻¹ and ultrastability for long-term testing of 120 h.

中文翻译：

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同时操纵体激子和表面缺陷以实现超稳定和高选择性 CO2 光还原

光催化 CO ₂还原 (PCR) 的目标是实现对单一含能产物的高选择性、高效率和稳定性。整体配置通常决定电荷载流子动力学，而表面原子排列定义 PCR 热力学途径。因此，本体和表面结构的并行工程对于实现 PCR 目标至关重要。在此，提出了使用通过创造性熔融策略合成的均匀掺杂的 BiOCl 纳米片的超稳定和高选择性 PCR。含 B ₂ O ₃作为熔盐和掺杂前体，这种新的掺杂方法确保了硼 (B) 从表面掺杂到具有双重功能的本体中。体 B 掺杂通过显着降低激子结合能来减轻限制在 2D BiOCl 中的强激子效应，而表面掺杂的 B 原子通过提取晶格羟基来重建 BiOCl 表面，导致紧密的 B-氧空位 (B-OV) 缔合。这些独特的 B-OV 关联物通过稳定 *COOH 以选择性生成 CO，从而实现自发的 CO ₂活化，抑制竞争性析氢并促进质子耦合电子转移步骤。因此，均匀的 B 掺杂 BiOCl 纳米片对 CO ₂表现出 98% 的选择性在可见光下还原一氧化碳，令人印象深刻的 83.64 µmol g ^-1 h ^-1速率和 120 小时长期测试的超稳定性。