The　photo-electrochemical　(PEC)　oxidation　of　glycerol　(GLY)　to　high-value-added　dihydroxyacetone　(DHA)　can　be　achieved　over　a　BiVO4　photoanode,　while　the　PEC　performance　of　most　BiVO4　photoanodes　is　impeded　due　to　the　upper　limits　of　the　photocurrent　density.　Here,　an　enhanced　Mie　scattering　effect　of　the　well-documented　porous　BiVO4　photoanode　is　obtained　with　less　effort　by　a　simple　annealing　process,　which　significantly　reduces　the　reflectivity　to　near　zero.　The　great　light　absorbability　increases　the　basic　photocurrent　density　by　1.77　times.　The　selective　oxidation　of　GLY　over　the　BiVO4　photoanode　results　in　a　photocurrent　density　of　6.04　mA　cm−2　and　a　DHA　production　rate　of　325.2　mmol　m−2　h−1　that　exceeds　all　reported　values.　This　work　addresses　the　poor　ability　of　nanostructured　BiVO4　to　harvest　light,　paving　the　way　for　further　improvements　in　charge　transport　and　transfer　to　realize　highly　efficient　PEC　conversion.　©　2023　Wiley-VCH　GmbH.