Metal/metal-oxide heterostructured nanoparticle arrays via block copolymer nanopatterning

Abstract

Vertically oriented block copolymer cylindrical nanotemplates provide a constant-geometry route to periodic nanoparticle arrays with predefined size and pitch, yet an easy and general route to periodic, co-localized metal/metal-oxide (M–MO) nanoparticle arrays remains limited. Here we report a nanotemplate-guided hybrid infiltration strategy that sequentially couples liquid-phase infiltration (LPI) with sequential infiltration synthesis (SIS) to generate compositionally tunable M–MO nanoparticle arrays while preserving the template geometry. This sequential protocol expands the accessible precursor space beyond that of either method alone and yields clearly defined M–MO architectures across multiple metal and metal-oxide combinations, with mechanistic insights and scalable fabrication over large areas. As a proof of concept, the resulting arrays serve as highly active hydrogen evolution reaction (HER) catalyst substrates and outperform the corresponding single-metal arrays with identical geometric configurations. Coverage-dependent density functional theory (DFT) calculations on Pt and Pt-ZnO surfaces further rationalized the interfacial synergy by quantifying the hydrogen adsorption free energy as a function of hydrogen coverage. This hybrid infiltration platform enables geometry-matched M–MO libraries for quantitative evaluation of interfacial effects in electrocatalysis and related interfacial-function devices.