CuBi2O4 photocathode with integrated electric field for enhanced H2O2 ???????production

Metal oxide semiconductors are promising for photosynthetic H2O2 & nbsp;production, provided the issue of excessive charge recombination can be adequately addressed. Inducing internal electric field is a common remedial strategy to inhibit carrier recombination but challenging to accomplish without external power input. To overcome this drawback, a novel photocathode was designed and fabricated by combing photothermoelectricity and photoelectricity by adding a NaCo2O4 film under the CuBi2O4 & nbsp;film to generate an internal electric field from photoinduced temperature gradients. Our results show the significantly enhanced photoelectrochemical activity for the composite photocathode with an H2O2 & nbsp;production concentration of 192.9 mu mol/L, 2.4 times higher than CuBi2O4 . Photocurrent under controlled temperature gradients and COMSOL simulation defined that the enhancement comes from the synergy of photothermoelectricity and photoelectricity. This work demonstrates a feasible strategy to inhibit carrier recombination in photoelectrode with internal thermoelectric potential, which can significantly enhance the energy conversion efficiency without extra energy consumption.