Cu₉S₅ possesses high hole concentration and potential superior electrical conductivity as a novel p-type semiconductor, whose biological applications remain largely unexploited. Encouraged by our recent work that Cu₉S₅ has enzyme-like antibacterial activity in the absence of light, which may further enhance the near infrared (NIR) antibacterial performance. Moreover, vacancy engineering can modulate the electronic structure of the nanomaterials and thus optimize their photocatalytic antibacterial activities. Here, we designed two different atomic arrangements with same V_CuSCu vacancies of Cu₉S₅ nanomaterials (CSC-4 and CSC-3) determined by positron annihilation lifetime spectroscopy (PALS). Aiming at CSC-4 and CSC-3 as a model system, for the first time, we investigated the key role of different copper (Cu) vacancies positions in vacancy engineering toward optimizing the photocatalytic antibacterial properties of the nanomaterials. Combined with the experimental and theoretical approach, CSC-3 exhibited stronger absorption energy of surface adsorbate (LPS and H₂O), longer lifetime of photogenerated charge carriers (4.29 ns), and lower reaction active energy (0.76 eV) than those of CSC-4, leading to the generation of abundant ·OH for attaining rapid drug-resistant bacteria killed and wound healed under NIR light irradiation. This work provided a novel insight for the effective inhibition of drug-resistant bacteria infection via vacancy engineering at the atomic-level modulation.

Cu ₉ S ₅作为新型p型半导体具有高空穴浓度和潜在的优异导电性，其生物应用在很大程度上仍未开发。受我们最近的工作鼓舞，Cu ₉ S ₅在没有光的情况下具有类似酶的抗菌活性，这可能进一步增强近红外 (NIR) 抗菌性能。此外，空位工程可以调节纳米材料的电子结构，从而优化其光催化抗菌活性。在这里，我们设计了两种具有相同V _CuSCu空位的不同原子排列的 Cu ₉ S ₅纳米材料 ( CSC-4和CSC-3 ) 由正电子湮没寿命谱 (PALS) 确定。针对CSC-4和CSC-3作为模型系统，我们首次研究了不同铜 (Cu) 空位位置在空位工程中对优化纳米材料光催化抗菌性能的关键作用。结合实验和理论方法，CSC-3表现出比CSC更强的表面吸附质（LPS 和 H ₂ O）吸收能，更长的光生载流子寿命（4.29 ns）和更低的反应活性能量（0.76 eV）-4, 导致大量的·OH 产生，从而在 NIR 光照射下实现快速杀死耐药细菌和愈合伤口。这项工作为通过原子级调制的空位工程有效抑制耐药细菌感染提供了新的思路。