Bismuth vanadate (BiVO 4 ) is an attractive, low-cost n-type semiconductor that exhibits excellent photoelectrocatalytic properties, chemical stability, and biocompatibility. This study reports a newly discovered function of BiVO 4 dissociating highly stable, self-assembled amyloid aggregates associated with Alzheimer's disease. A visible light-active, nanoporous BiVO 4 platform is developed to break β-amyloid (Aβ) assemblies and alleviate Aβ aggregateinduced toxicity. Multiple photochemical and microscopic analyses reveal that β-sheet-rich, long Aβ fibrils are effectively destabilized and broken into small-sized, soluble species by BiVO 4 photoelectrode under illumination of a white light-emitting diode and an anodic bias. The photoactivated BiVO 4 under anodic bias generates oxidative stress, such as superoxide ions and hole-derived hydrogen peroxide, which causes photooxidation of Aβ residues and irreversible disassembly of Aβ aggregates. The efficacy of photoelectrocatalytic dissociation of Aβ aggregates is enhanced by Mo-doped BiVO 4 , which facilitates the separation of electron-hole pairs by improving electrontransport properties of BiVO 4 . Furthermore, it is verified that both pristine and Mo-doped BiVO 4 photoelectrodes are nontoxic and effective in reducing Aβ-associated cytotoxicity. The work shows the potential of BiVO 4 -based photoelectrode platforms for the dissociation of neurotoxic, highly stable Aβ assemblies using light energy.