Artificial photosynthesis emerges as feasible solution to diminish CO2content in the atmosphere. Photoelectrocatalysis can diminish CO2concentration while generating useful resources such as methanol. Here an alternative multilayer photoelectrode of FTO/Cu/Bi2Se3-Se/Cu2O is developed to enhance selective reduction of CO2 towards methanol. A novel electrosynthetic approach is described as strategy to modulate the atomic composition of p-type bismuth selenide chalcogenide intralayer. This method enhanced performance and selectivity of n-type Cu2O photoelectrocatalysts. Alkaline pH conditions favored yield and selectivity towards methanol production from CO2. The formation of an n-p heterojunction affects the Cu2Operformance on CO2reduction. The novel engineered FTO/Cu/Bi2Se3-Se/Cu2O multilayer photoelectrodes allowed obtaining up to 4.5mM of methanol, which correspond to 3-fold higher concentration than conventional FTO/Cu2O electrodes reported in literature. Photoelectrodes of FTO/ Cu/Bi2Se3-Se/Cu2O overperform conventional Cu2O in terms of kinetics and selectivity towards methanol production.