In this study, we show that enzymatic reactions can be easily enhanced by visible light irradiation. It is a general method as demonstrated by several different types of enzymes, including amylase, cellulase and lipase, which are typically utilized in many industrial biocatalysis processes. Markedly different from conventional titanium dioxide (TiO2) nanoparticles which absorb UV light and generate little thermal energy, defect-rich Magnéli phase titanium oxide (Ti8O15) nanoparticles absorb solar light and provide a highly effective solar-to-thermal conversion, which greatly enhances enzymatic reactions. This accelerating effect, together with the biocompatibility, high chemical stability and easy preparation of Ti8O15 nanoparticles, makes this method appealing for enhancing the efficiency of biocatalysis.