Cu2O/CuO heterojunction catalysts through atmospheric pressure plasma induced defect passivation

A novel route to fabricate Cu2O/CuO heterojunction electrodes using an atmospheric pressure plasma jet (APPJ) is demonstrated. This process promotes favourable band alignment and produces nanoscale CuO surface features from Cu2O with low density of interfacial defects. electrode can operate without any transparent current collector, showing remarkable currents stability towards oxygen evolution reaction (OER) (6 mA cm?2 for 2 h at pH14) as well photocatalytic hydrogen (HER) activity (?1.9 800 s pH7). When the electrocatalytic was measured deposited on FTO substrate increased ~40 0.8 V vs SCE in 1 M KOH compensating electrolyte resistance (iR correction). The composite films also exhibited a high rate photo degradation Methylene Blue (MB) phenol visible spectra, indicating efficient charge separation. We modelled electronic structure this epitaxially grown functional theory. calculations revealed distinctive shifts Fermi level p-band centre O atom d-band Cu interface contribute catalytic heterostructure. Another factor influencing stems excited species introducing polar radicals increasing coverage. work presents potential APPJ functionalization tune properties copper oxide based catalysts enhanced efficiency OER HER water splitting.