10% Efficient Solar-to-Hydrogen Generation Via Organic Semiconductor with Ni-Heazlewoodite Electrocatalysts

A 10% efficient and cost-effective solar-to-hydrogen conversion device was developed through the integration of low-cost Ni Heazlewoodite-based catalysts for the hydrogen evolution reaction (HER) and ternary bulk heterojunction organic semiconductor (OS)-based light absorbers. Se-incorporated Ni₃S₂ was synthesized by a one-step hydrothermal method, which demonstrated a low over potential and Tafel slope, indicative of its superior HER activity. The theoretical calculation results validate the enhanced HER performance of the Se-Ni₃S₂ catalyst in alkaline electrolytes. The ternary phase organic light absorber is designed to generate tailored photovoltage and maximized photocurrent, allowing a photocurrent density of 8.24 mA cm⁻²under unbiased conditions. Low temperature photoluminescence spectroscopy results revealed that the enhanced photocurrent density originates from a reduction in both phonon- and vibration-induced inter- and intramolecular non-radiative decay.