Valorization of wheat straw: Rapid reduction of CuO into Cu and production of organic acids under mild hydrothermal conditions

•A rapid and facile method for conversion of CuO into Cu was proposed.•Wheat straw was employed as a reductant for reducing CuO to Cu.•More than 90% yield of Cu was obtained for 1–3h under mild hydrothermal conditions.•Wheat straw was converted to value-added products such as lactic acid and acetic acid.