Mesoporous graphitic carbon nitride-supported binary MPt (M: Co, Ni, Cu) nanoalloys as electrocatalysts for borohydride oxidation and hydrogen evolution reaction

Abstract

In this work, binary MPt (M = Co, Ni, Cu) nanoalloys and mesoporous carbon nitride (mpg-C3N4) as support material are prepared, and then gathered together by liquid phase self-assembly in order to produce MPt/mpg-C3N4 electrocatalysts. The yielded electrocatalysts are characterized by TEM, ICP-MS and XRD techniques in order to determine their morphology, composition and textural properties. Evaluation of MPt/mpg-C3N4 (<3 wt.% of Pt) electrocatalysts performance for hydrogen evolution reaction (HER) and borohydride oxidation reaction (BOR) is carried out. Pt/mpg-C3N4 is also studied to better understand the alloying effect on the electrocatalysts’ performance, being concluded that it clearly increases the catalytic activity while decreasing the necessary Pt metal amount. For HER, CoPt/mpg-C3N4 was found to be the best catalyst, presenting a Tafel slope of 109 mV dec−1 at 65 °C. Regarding BOR, CuPt/mpg-C3N4 demonstrated the best catalytic activity with average activation energy and reaction order with respect to BH4- of 29.4 kJ mol−1 and 0.87, respectively.