Biowaste-Derived Interconnected Carbon Nanosheet-Supported Iron as a Highly Stable and Excellent Electrocatalyst for Overall Water Splitting
Arunagiri Gayathri, Murugan Vijayarangan, Muthukumaran Sangamithirai, Venkatachalam Ashok, Jayaraman Jayabharathi, Venugopal Thanikachalam
Abstract
Water splitting needs low-cost materials that can efficiently catalyze both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). We prepared biowaste-derived self-nitrogen-doped interconnected hierarchically porous carbon nanosheet Fe@PSAC as a bifunctional and ultradurable electrocatalyst for water splitting. Fe@PSAC exhibits a low overpotential of 118 mV (84 mV/dec) for HER and 231 mV (66 mV/dec) for OER @ 10 mA/cm 2 in 1.0 M KOH (without iR correction). Fe@PSAC exhibits durability for 100 h with minimum potential losses of 2.9 and 2.3% for HER and OER, respectively. The turnover frequency of Fe@PSAC (0.2297/s) and IrO 2 (0.0231/s) for OER and Fe@PSAC (0.0784/s) and Pt/C (0.1806/s) for HER was nearer to Pt/C and greater than IrO 2, respectively. The synergy between self-nitrogen-doped interconnected hierarchically porous carbon nanosheets and iron endows excellent bifunctional activity and stability. The Fe@PSAC//Fe@PSAC water electrolyzer exhibits excellent activity at 1.58 V to reach 10 mA/cm 2 with high stability for 120 h with a 3.2% potential loss. The Fe@PSAC//Fe@PSAC electrocatalyst shows an exceptional activity of 1.58 V using solar-assisted water electrolysis. The Fe@PSAC//Fe@PSAC electrode has been strongly recommended for low-cost hydrogen fuel production on a large scale.