2D/2D Black Phosphorus/Nickel Hydroxide Heterostructures for Promoting Oxygen Evolution via Electronic Structure Modulation and Surface Reconstruction

摘要

2D heterostructures provide another exciting opportunity for extending theapplication of 2D materials in energy conversion and storage devices, dueto their flexibility in electronic structure modulations and surface chemistryregulations. Herein, by coupling liquid-exfoliated and mildly oxidized blackphosphorus nanosheets (BP-NSs) with wet-chemically synthesized 2D nickelNi(OH)2 nanosheets (NH-NSs), 2D/2D heterostructured nanosheets(BNHNSs) are rationally constructed with a favorable transition of electronstructure and desired intermediate adsorptions for alkaline oxygen evolutionreaction (OER) catalysis. When used as an OER catalyst, to reach a currentdensity of 10 mA cm~（?2）, the overpotential of 2D/2D BNHNSs is only 297 mV,corresponding to a considerable decrease of 22 and 34 compared with theindividual 2D NH-NSs and 2D BP-NSs, respectively. The structural tracking atthe initial reconstruction stage via time-dependent Raman spectra confirms thatthe phosphorus oxidization into the P–OH and the phase transformation intooxyhydroxide (NiOOH) significantly promote the electron transfer and electrocatalyticefficiency and thus endow the 2D/2D BNHNSs with much enhancedOER catalytic activity. This work offers new insights on the electron structuremodulation of 2D-based heterostructures and opens new avenues for regulatingthe adsorption of emerging phosphorene-based materials for electrocatalysis.