Efficient photocatalytic carbon monoxide production from ammonia and carbon dioxide by the aid of artificial photosynthesis

Ammonium bicarbonate (NH(4)HCO(3)) was generated by the absorption of carbon dioxide (CO(2)) into an aqueous solution of ammonia (NH(3)). NH(4)HCO(3) was successfully used to achieve highly efficient photocatalytic conversion of CO(2) to carbon monoxide (CO). NH(3) and/or ammonium ions (NH(4) (+)) derived from NH(4)HCO(3) in aqueous solution were decomposed into nitrogen (N(2)) and hydrogen (H(2)). Stoichiometric amounts of the N(2) oxidation product and the CO and H(2) reduction products were generated when the photocatalytic reaction was carried out in aqueous NH(4)HCO(3) solution. NH(3) and/or NH(4) (+) functioned as electron donors in the photocatalytic conversion of CO(2) to CO. A CO formation rate of 0.5 mmol h(–1) was obtained using 500 mg of catalyst (approximately 7500 ppm) in ambient conditions (303 K, 101.3 kPa). Our results demonstrated that NH(4)HCO(3) is a novel inorganic sacrificial reagent, which can be used to increase the efficiency of photocatalytic CO production to achieve one step CO(2) capture, storage and conversion.