Oxygen vacancy-rich Bi2WO6 nanocrystals for fast and wide-range photoelectrochemical sensing of hydrogen peroxide

•It presents a PEC sensor on oxygen vacancy rich Bi2WO6 to realize fast and wide-range detection of H2O2.•Bi2WO6-V exhibits a narrower band gap for efficient visible light harvesting, and a higher catalytic activity over Bi2WO6.•It delivers a wide linear range from 1.5 μM to 230 mM and a detection limit of 0.5 μM, higher than that of Bi2WO6 sensor.•It retains wide applications in early disease diagnosis, healthcare product screening, and food and environmental safety.