Ni integrated S-gC3N4/BiOBr based Type-II heterojunction as a durable catalyst for photoelectrochemical water splitting

Type-II heterojunction was demonstrated based on the construction of nickel incorporated sulfur-doped graphitic carbon nitride with bismuth oxybromide (Ni/S-gC3N4/BiOBr) interfaces by ultrasonically aided hydrothermal route. For the first time, photoelectrochemical (PEC) activity of Ni/S-gC3N4/BiOBr material investigated and the enhanced photocurrent density of 177.2 μA/cm2 at 1.23 V vs. RHE (1.68 mA/cm2 photocurrent density at 1.6 V vs. RHE at an overpotential of ca. 370 mV) in which 89-fold higher than S-gC3N4, 13-fold larger than BiOBr and 3-fold greater than S-gC3N4/BiOBr. The constructed Ni/S-gC3N4/BiOBr nanohybrid material possesses high durability up to 6000 s, and the ABPE acquired as 4.026 x 10−3 in which 10.7-fold greater than BiOBr and 84-fold higher than S-gC3N4. The HRTEM images and elemental mapping confirms the presence of nickel supported sulfur-doped graphitic carbon nitride and bismuth oxy bromide heterostructure obtained with interfaces. The kinetic parameters such as charge transfer resistance, charge carrier density that could confirm the effective charge separation and migration at the electrode/electrolyte interfaces. This work illustrates broaden of BiOBr material was explored in PEC water splitting with a new insight of cocatalyst engineering and design the construction of Type-II heterojunctions utilized with renewable energy sources for photoelectrocatalysis.