Procedure:-

● Clean the conducting glass ITO substrate by sonicating it in a detergent solution for 10 minutes, ethanol for 20 minutes, and distilled water for 30 minutes.
● Prepare the precursor solutions A, B, and C.
● For solution A, weigh 0.0125 gm of sodium tungstate and transfer to a 100 mL volumetric flask, and make up with distilled water.
● For solution B, weigh 0.015 gm of hydrogen peroxide and transfer to a 100 mL volumetric flask, and make up with distilled water.
● For solution C, pipette 3.2 mL nitric acid into a 100 mL volumetric flask and make up with distilled water.
● Transfer these precursor solutions A (sodium tungstate dehydrate solution), B (hydrogen peroxide solution), and C (nitric acid solution) into the electrochemical cell one by one.
● Pour 5ml of each solution and set the three-electrode system using ITO as a working electrode, Ag/AgCl electrode as a reference electrode, and Pt electrode as a counter electrode, respectively.
● The amperometric method was optimized by keeping a constant potential at 0.5 V and varying the deposition time.
● The graph shows the photocurrent response from water oxidation of the ITO/WO 3 electrode prepared with the amperometric method with various deposition times of 15 min, 30 min, and 45 minutes.