Mg‐O Bridged Polypyrrole/g‐C3N4 Nanocomposites as Efficient Visible‐light Catalysts for Hydrogen Evolution

It is highly desired to improve the visible-light activity of g-C 3 N 4 for H 2 evolution by constructing closely-contacted heterojunctions with conductive polymers. Herein, a polymer nanocomposite photocatalyst with high visible-light activity was successfully fabricated by coupling nano-sized polypyrrole (NPPy) particles onto g-C 3 N 4 nanosheets through a simple wet-chemical process and its visible-light activity is further improved by constructing Mg-O bridges between the NPPy and g-C 3 N 4 . The amount-optimized bridged nanocomposite displays a ~9-time visible-light activity improvement compared to g-C 3 N 4 . Based on transient-state surface photovoltage responses and photoluminescence spectra, *OH amount evaluation and photoelectrochemical curves, it is concluded that the exceptional photoactivity is attributed to the significantly promoted charge transfer and separation along with visible photosensitization from NPPy. Interestingly, it is confirmed that the promoted charge separation mainly depends on the excited high-level electron transfer from g-C 3 N 4 to NPPy by single-wavelength photocurrent action spectra. This work provides a feasible strategy for designing polymer nano-heterojunction photocatalysts with exceptional visible-light activities.