Single-Precursor to Dual-Function: A Transformable Metal-Organic Framework Nanoplatform for Photocatalytic H2 Evolution and CO2 Reduction.

Precisely engineered nanoplatforms capable of controlled structural evolution from atomically dispersed sites to confined nanoparticles provide opportunities for multifunctional solar fuel production. Herein, we report a "two-in-one" photocatalytic strategy based on a transformable metal-organic framework (MOF) nanoplatform that enables two distinct solar fuel pathways from a single precursor. Microwave-assisted atomic-level engineering affords Pt1/In2O3/UiO-66-NH2, a nanostructured composite featuring atomically dispersed Pt sites anchored within an In2O3-modified MOF architecture. This atomic-scale configuration delivers efficient visible-light-driven H2 evolution with a rate of 2749.6 μmol g-1 h-1, aided by favorable hydrogen adsorption energy (ΔGH* = -0.39 eV). Controlled pyrolysis transforms the same precursor into PtNP/In2O3/N-C, in which confined Pt nanoparticles (2.3 ± 0.4 nm) are embedded in a conductive N-doped carbon matrix, enabling efficient photocatalytic CO2-to-CO conversion with a CO production rate of 4758.1 μmol g-1 h-1. This work demonstrates how controlled atomic-to-nanoscale structural evolution within a unified MOF-derived platform can direct functional specialization, providing a design principle for multifunctional photocatalytic systems.