Persistent CO2 photocatalysis for solar fuels in the dark

The hydrogenation of CO2 to hydrocarbon fuels via solar radiation offers a sustainable pathway towards a carbon-neutral energy cycle. However, the reaction is hindered by the intermittent availability of sunlight. This critical issue could be mitigated by engineering a materials system, known as persistent photocatalysis, that prolongs solar fuel production during overcast periods and into the evenings. During illumination, charge can be stored in a suitable capacitor or battery-like material that interfaces with the photocatalyst, while discharging occurs postillumination to continue driving the catalytic reaction. We discuss emerging trends and materials strategies to develop these catalyst systems and prolong the operation of photocatalysis. The photocatalytic conversion of CO2 to fuels could contribute to a carbon-neutral energy cycle, but it works only when sunlight is available. Here the authors propose a persistent photocatalyst system that prolongs solar fuel production and discuss emerging trends and design strategies.