Solution-polarized biodegradable nano-hydroxyapatite for efficient H2O2 generation via contact-electro catalysis

Contact-electro-catalysis (CEC) holds promise for in vivo therapeutics but is constrained by the non-biodegradable nature of typical catalyst materials, raising biosafety concerns. To address this, we developed a biodegradable CEC catalyst using nano-hydroxyapatite (nHAp). Its surface polarization was enhanced by modulating OH − ion orientation via treatment with p-fluorobenzoic acid. This polarization improved nHAp's crystallinity, as shown by a decrease in the (002) X-ray diffraction peak full width at half maximum from 0.29 to 0.21, and increased its surface potential by 1.97-fold. The polarized nHAp demonstrated significantly enhanced reactive oxygen species generation: ·OH and 1 O 2 production increased by 1.9-fold and 1.1-fold, respectively, and H 2 O 2 yield reached 340.2 μM/h—approximately 10 times higher than corona-poled nHAp. Notably, under hypoxic saline conditions mimicking pathological environments, polarized nHAp produced sufficient H 2 O 2 to meet the threshold for effective cancer cell ablation, highlighting its therapeutic potential.