Graphene oxide mediated self-sacrificial synthesis of LaCO3OH-Ni(OH)2@graphene hierarchical composite for photocatalytic H2 evolution and supercapacitor

Abstract

Herein, we designed a one-step lattice-confined etching perovskite nanoparticles and self-sacrificing graphene oxide (GO) induced self-assembly strategy to synthesize novel 3D nest-like LaCO3OH and flower-like Ni(OH)2@graphene (RGO) hierarchical composite as a high performance photocatalyst and electrode material. The lattice-confined effect regulates the concentration and distribution of nickel ions migrating from perovskite to GO and thus constructs a homogeneous Ni(OH)2@RGO nanostructure. La(OH)3 formed by residual lattice frames react with CO32− from self-sacrificing of GO self-assembly to form nest-like LaCO3OH, which is embedded in the Ni(OH)2@RGO nanosheets. GO was utilized as both morphology control reagent and self-sacrificed carbon source. Benefit from the extremely rapid transfer of electron on the homogeneous Ni(OH)2@RGO nanosheets and high light-harvesting capacity of 3D nest and flower-like composite of LaCO3OH-Ni(OH)2@RGO, the properties of photocatalysis and supercapacitor are greatly enhanced. The H2 production rate of 1.3807 mmol h−1 g−1 has been achieved which is 13 times higher than pure LaCO3OH. Electrochemical studies showed that a specific capacitance of 572.47 F g−1 was obtained at a scan rate of 10 mv/s with 80% capacitance retention even after 20,000 cycles. This composite synthesized from GO mediated etching solid phase perovskite surface ion migration under lattice-confined action provides a novel technical route for the direct self-assembly of solid nanoparticles and GO to synthesize new functional materials.