TY - JOUR
T1 - Bifunctional and Self-Supported NiFeP-Layer-Coated NiP Rods for Electrochemical Water Splitting in Alkaline Solution
AU - Diao, Fangyuan
AU - Huang, Wei
AU - Ctistis, Georgios
AU - Wackerbarth, Hainer
AU - Yang, Yuan
AU - Si, Pengchao
AU - Zhang, Jingdong
AU - Xiao, Xinxin
AU - Engelbrekt, Christian
PY - 2021
Y1 - 2021
N2 - Designing efficient and robust nonprecious metal-based electrocatalysts for overall water electrolysis, which is mainly limited by the oxygen evolution reaction (OER), for hydrogen production remains a major challenge for the hydrogen economy. In this work, a bimetallic NiFeP catalyst is coated on nickel phosphide rods grown on nickel foam (NiFeP@NiP@NF). This self-supported and interfacially connected electrode structure is favorable for mass transfer and reducing electrical resistance during electrocatalysis. The preparation of NiFeP@NiP@NF is optimized in terms of (i) the coprecipitation time of the NiFe Prussian blue analogue layer that serves as phosphides precursor and (ii) the phosphidation temperature. The optimized sample exhibits excellent OER performance delivering current densities of 10 and 100 mA cm-2 at low overpotentials of 227 and 252 mV in 1.0 M KOH, respectively, and maintaining 10 mA cm-2 for more than 120 h without obvious degradation. Moreover, it can also be operated as a hydrogen evolution electrocatalyst, requiring an overpotential of 105 mV at 10 mA cm-2 in the same medium. Thus, the as-prepared material was tentatively utilized as a bifunctional electrocatalyst in a symmetric electrolyzer, requiring a voltage bias of 1.57 V to afford 10 mA cm-2 in 1.0 M KOH, while exhibiting outstanding stability.
AB - Designing efficient and robust nonprecious metal-based electrocatalysts for overall water electrolysis, which is mainly limited by the oxygen evolution reaction (OER), for hydrogen production remains a major challenge for the hydrogen economy. In this work, a bimetallic NiFeP catalyst is coated on nickel phosphide rods grown on nickel foam (NiFeP@NiP@NF). This self-supported and interfacially connected electrode structure is favorable for mass transfer and reducing electrical resistance during electrocatalysis. The preparation of NiFeP@NiP@NF is optimized in terms of (i) the coprecipitation time of the NiFe Prussian blue analogue layer that serves as phosphides precursor and (ii) the phosphidation temperature. The optimized sample exhibits excellent OER performance delivering current densities of 10 and 100 mA cm-2 at low overpotentials of 227 and 252 mV in 1.0 M KOH, respectively, and maintaining 10 mA cm-2 for more than 120 h without obvious degradation. Moreover, it can also be operated as a hydrogen evolution electrocatalyst, requiring an overpotential of 105 mV at 10 mA cm-2 in the same medium. Thus, the as-prepared material was tentatively utilized as a bifunctional electrocatalyst in a symmetric electrolyzer, requiring a voltage bias of 1.57 V to afford 10 mA cm-2 in 1.0 M KOH, while exhibiting outstanding stability.
U2 - 10.1021/acsami.1c03089
DO - 10.1021/acsami.1c03089
M3 - Journal article
C2 - 33974401
SN - 1944-8244
VL - 13
SP - 23702
EP - 23713
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 20
ER -