Unprecedented urea oxidation on Zn@Ni-MOF with an ultra-high current density: understanding the competition between UOR and OER, catalytic activity limitation and reaction selectivity

Abstract

Zn-doping populates the catalytically active Ni3+-OOH sites, and subsequently prevents the detrimental competition between the UOR and OER. Consequently, Zn@Ni-MOF demonstrates an outstanding ultra-high UOR current density.

Ni5P4-embedded FeV LDH porous nanosheets for enhancing oxygen evolution and urea oxidation reactions

“…At a certain bias potential, when the formation of Ni 3+ –OOH site is slower than its consumption, an UOR–OER trade-off zone will be formed. 54 Obviously, compared with the sample in alkaline solution, there is a significant boost in the catalyst activity in the electrolyte with urea. As profiled in Fig.…”

Green and sustainable bifunctional carbonized wood electrodes decorated with controlled nickel/α(β)-nickel(ii) hydroxide to boost overall water splitting

“…The OER curves of Ni/Ni(OH) 2 /CW consisted of the peaks of the oxidation of Ni(OH) 2 before oxygen evolution. 15,19,22,39,43,46,55,56 Ni(OH) 2 undergoes two types of oxidations to afford NiOOH:α-Ni(OH) 2 + OH − → γ-NiOOH + H 2 O + e − β-Ni(OH) 2 + OH − → β-NiOOH + H 2 O + e − …”

Metal-ion doping in metal–organic-frameworks: modulating the electronic structure and local coordination for enhanced oxygen evolution reaction activity

“…For an example, the XPS and XRD peak shift of the pristine Ni-MOF was observed after doping with Zn. 50 The enhanced charge transfer capability after doping can be identified through the reduced charge transfer resistance in the Nyquist plot obtained from electrochemical impedance spectroscopy (EIS), as shown in Fig. 3E.…”