Well-defined core/shell pDA@Ni-MOF heterostructures with photostable polydopamine as electron-transfer-template for efficient photoelectrochemical H2 evolution

Here, novel core/shell polydopamine@Ni-MOF (pDA@Ni-MOF) heterogeneous nano structures are synthesized via a simple one-pot nucleation-growth technique. This rational core/shell design method provide a uniform Ni-MOF shell thickness (shell: ~ 10 nm) as well as homogeneous wrapping of pDA templates with quite narrow size distributions. The obtained band properties of bare pDA (E-CB=-0.35 eV and E-VB = 2.95 eV vs normal hydrogen electrode (NHE)) and bare Ni-MOF (E-CB=-0.49 eV and E-VB = 2.85 eV vs NHE) clearly revealed charge separation is occurred on pDA by absorbing light due to pi-pi* transition, and photogenerated electrons on conduction band (CB) of pDA was migrated to CB of Ni-MOF. Specifically, the photoelectrochemical (PEC) water performance of pDA@Ni-MOF photo anodes with highest current density is recorded as 8.61 mA/cm(2) at 0.77 V vs. RHE under visible LED irradiation, which is significantly higher than bare pDA (0.008 V vs. RHE) and bare Ni-MOF (0.011 V vs. RHE) at the same conditions. Note that, the higher photon absorption properties of pDA in core together with high interaction valence bond between two semiconductors could generate electron rich state giving rise to faster electron transfer kinetics as next generation of MOF based hybrid materials with regular morphologies. (C)& nbsp;2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.