A New Strategy for Solar‐to‐Hydrogen Energy Conversion: Photothermal‐Promoted Electrocatalytic Water Splitting

Abstract Solar‐to‐hydrogen (STH) energy conversion can be typically realized by photocatalytic water splitting, photoelectrochemical water splitting, and photovoltaic water electrolysis. Herein, we propose a new strategy for STH energy conversion based on photothermal‐promoted electrocatalysis (PTPE). First, carbon hemispheres were developed with strong capability of collecting and concentrating heat by absorbing photons (>630 nm). Second, we incorporated two representative materials, Co(OH) 2 and MoS 2 , with the heat collectors (carbon hemispheres) as electrocatalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively. The two hybrids showed enhanced electrocatalytic activity of water splitting under light irradiation, owing to the elevated local temperature of carbon that had been heated by the light. PTPE might be widely applied in electrocatalytic systems for solar energy utilization via a simple STH and subsequent heat‐promoted electrosynthesis route.