Electrochemically active and robust cobalt doped copper phosphosulfide electro-catalysts for hydrogen evolution reaction in electrolytic and photoelectrochemical water splitting

• Published in: International journal of hydrogen energy Vol. 43; no. 16; pp. 7855 - 7871
• Main Authors: Patel, Prasad Prakash, Velikokhatnyi, Oleg I., Ghadge, Shrinath D., Hanumantha, Prashanth J., Datta, Moni Kanchan, Kuruba, Ramalinga, Gattu, Bharat, Shanthi, Pavithra Murugavel, Kumta, Prashant N.
• Format: Journal Article
• Language: English
• Published: United Kingdom Elsevier Ltd 19.04.2018; Elsevier
• Subjects: Copper phosphide; Hydrogen evolution reaction; Phosphosulfide; Sulfur doping; Water splitting; Phosphosulfide; Copper phosphide; Hydrogen evolution reaction; Water splitting; Sulfur doping
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2018.02.147

The area of non-noble metals based electro-catalysts with electrochemical activity and stability similar or superior to that of noble metal electro-catalyst for efficient hydrogen production from electrolytic and photoelectrochemical (PEC) water splitting is a subject of intense research. In the current study, exploiting theoretical first principles study involving determination of hydrogen binding energy to the surface of the electro-catalyst, we have identified the (Cu0.83Co0.17)3P: x at. % S system displaying excellent electrochemical activity for hydrogen evolution reaction (HER). Accordingly, we have experimentally synthesized (Cu0.83Co0.17)3P: x at. % S (x = 10, 20, 30) demonstrating excellent electrochemical activity with an onset overpotential for HER similar to Pt/C in acidic, neutral as well as basic media. The highest electrochemical activity is exhibited by (Cu0.83Co0.17)3P:30 at. % S nanoparticles (NPs) displaying overpotential to reach 100 mA cm−2 in acidic, neutral and basic media similar to Pt/C. The (Cu0.83Co0.17)3P:30 at. % S NPs also display excellent electrochemical stability in acidic media for long term electrolytic and PEC water splitting process [using our previously reported (Sn0.95Nb0.05) O2: N-600 nanotubes (NTs) as the photoanode]. The applied bias photon-to-current efficiency obtained using (Cu0.83Co0.17)3P:30 at. % S NPs as the cathode electro-catalyst for HER in an H-type PEC water splitting cell (∼4%) is similar to that obtained using Pt/C (∼4.1%) attesting to the promise of this exciting non-noble metal containing system. [Display omitted] •Nanostructured (Cu0.83Co0.17)3P:S studied as HER electro-catalysts.•(Cu0.83Co0.17)3P:30 at.% S showed similar overpotential at 100 mA/cm2 to Pt/C.•(Cu0.83Co0.17)3P:S show excellent electrochemical stability in acidic media.•(Cu0.83Co0.17)3P:30 at.% S exhibits similar ABPE to Pt/C in PEC cell.•DFT calculations validate superior catalytic activity of (Cu0.83Co0.17)3P:S.