This article presents the reduction of carbon dioxide (CO2) to products using solar energy on Zn and Sn electrocatalysts. Cobalt oxide (Co3O4) electrode was used as an anode for water dissociation reaction. Zinc (Zn) and tin (Sn) electrocatalysts were used as cathodes for photo electrochemical reduction of CO2. The extent of CO2 reduction was investigated in presence of various concentrations of bicarbonates of sodium and potassium electrolytes. The samples were collected for the reaction time of (10, 20, 30, 40, 50 and 60 min) and analyzed by using ultra fast liquid chromatography (UFLC). Formic acid (HCOOH) was the only product formed for both the electrocatalysts and respective results and optimized conditions were given in detail. Maximum HCOOH formed in 0.2 M KHCO3 for 10 min reaction was 430 mu mol and 400 mu mol using Sn and Zn electrocatalyst, respectively. On the other hand, 0.2 M NaHCO3 produced 494.6 mu mol and 176 mu mol of HCOOH after 10 min using Sn and Zn electrocatalyst, respectively. Therefore, the work is worthy for single product formation from CO2 and water using inexpensive and efficient electrocatalysts. (C) 2015 Elsevier Ltd. All rights reserved.