Photoelectrocatalytic Reduction of CO(2) to Paraffin Using p-n Heterojunctions

Nowadays, photoelectrocatalytic (PEC) reduction of CO(2) represents a very promising solution for storing solar energy in value-added chemicals, but so far it has been hampered by the lack of highly efficient catalyst of photocathode. Enlightened by the Calvin cycle of plants, here we show that a series of three-dimensional C/N-doped heterojunctions of Zn(x):Co(y)@Cu are successfully fabricated and applied as photocathodes in the PEC reduction of CO(2) to generate paraffin product. These materials integrate semiconductors of p-type Co(3)O(4) and n-type ZnO on Cu foam to construct fine heterojunctions with multiple active sites, which result in excellent C-C coupling control in reduction of CO(2). The best catalyst of Zn(0.2):Co(1)@Cu yields paraffin at a rate of 325 μg·h(−1) under −0.4 V versus saturated calomel electrode without H(2) release. The apparent quantum efficiency of PEC cell is up to 1.95%.