Abstract: Method for visible-light driven oxidation of aldehydes to carboxylic acid using carbon dioxide (CO2) as the oxidant in the absence of any catalyst are provided. In the disclosed process, aldehydes, when reacted with CO2 in an organic solvent, either in a batch reactor or in a continuous flow reactor, under conditions of ambient temperature and pressure, using a readily available household LED lamp, yield corresponding carboxylic acids along with the formation of carbon monoxide (CO) in the effluent gas.