Engineering vacancy-defective carbon nitride nanowire clusters for dramatically enhanced visible-light-driven photocatalytic H2O2 production

Graphitic carbon nitride (g-C3N4) is recognized as a sustainable and cost-effective alternative for hydrogen peroxide (H2O2) production, but its efficiency is fundamentally hindered by intrinsic limited surface area, charge separation, and light absorption. In this study, we propose an innovative strategy to address these issues by engineering vacancy-defective g-C3N4 nanowire clusters. The resulting nanowire clusters, with enhanced surface area and uniformly distributed carbon vacancies, exhibit a remarkable H2O2 production rate of 4.11 mmol g-1 h-1 under visible light irradiation, representing an approximately 15-fold improvement over bulk g-C3N4. The engineered carbon vacancies are shown to enhance O2 adsorption and reduce the energy barrier for *OOH hydrogenation to H2O2, thereby enabling a highly efficient and selective oxygen reduction reaction (ORR). Furthermore, the material demonstrates a tetracycline hydrochloride degradation rate of up to 81.98%, highlighting its promising potential for environmental applications. Notably, this work is the first to report the unique nanowire cluster morphology of g-C3N4, which, in conjunction with defect engineering, offers new insights into the development of advanced photocatalysts for H2O2 production. Compared to most previously reported defect-modified g-C3N4 materials, the photocatalytic performance of our nanowire clusters is significantly superior, marking an important advancement in the field.