Effective H₂O₂ Production from the Radiolysis of Oxygenated Water Assisted by WO₃ Nanoparticles-Encapsulated Nickel-Based Metal Hydroxide–Organic Framework

Radiolysis of oxygenated water can produce H2O2 via primary •OH radical recombination and hydrated electron (eaq–) transfer to O2, which is a direct, decentralized, and sustainable process for overall H2O2 synthesis. However, the practicality suffers from poor yield due to low ionizing efficiency and completion of redox reactions. Here, a WO3 nanoparticles-encapsulated nickel-based metal hydroxide–organic framework (Ni-MHOF) is synthesized via a one-step hydrothermal method as a catalyst to address the challenges. Remarkably, it achieves a H2O2 formation yield of ∼0.67 μmol J–1 and a ray-to-chemical conversion efficiency of 8.1% over multiple X-ray irradiation cycles, in the absence of any scarifying agents or electrolytes. Operando experiments using pulse radiolysis and customized in situ X-ray-coupled spectroscopy highlighted the unique capability of Ni-MHOF acting as a radiation-resistant nanoreactor to accelerate eaq–-driven O2 reduction and bind the key *OOH intermediates on Ni metal sites. Moreover, the porous structure and periodic arrays facilitate WO3 nanoparticles dispersion and their radiosensitizing merit to produce more •OH radicals while avoiding undesirable H2O2 dissociation on the surface. The application prospect is further enhanced by using a desktop electron beam to produce H2O2 at a rate of 16.2 mmol/gcat/h, and an effective degradation of organic waste enabled by as-synthesized H2O2.