Enhanced photocatalytic removal of NOx through the synergistic effect of photothermal activation and bipyroelectricity

•The introduction of PVDF can improve the directional migration of photogenerated charge carriers.•The photothermal effect of carbon black can rapidly increase the surface temperature of the entire system.•The photothermal conversion properties and the dual pyroelectricity interact synergistically, which improves the photocatalytic denitration efficiency. Photocatalysis provides a green and promising strategy for removing nitrogen oxides (NOx), one of the main pollutants in the atmosphere. However, few studies have been able to utilize the infrared portion of sunlight due to its low energy, which accounts for >50% of the total sunlight. The conversion of infrared light into heat is an effective but flawed approach for photocatalysis, because high temperature cannot only reduce the activation barrier of the reaction and improve the migration rate of charge carriers, but also increase the collision probability of photogenerated carriers. Here, C/PVDF-BaTiO3 (polyvinylidene fluoride, PVDF) photocatalytic films with bi-pyroelectric effect are designed to boost the full-spectrum solar photocatalytic conversion of NOx. During the photocatalytic reaction process, the photothermal conversion of carbon and the dual pyroelectricity synergistically enhance and reinforce each other’s effects. The 0.5 wt% C/PVDF-BaTiO3 film achieves a denitrification efficiency of 60% in a flow reaction, surpassing both the BaTiO3 and PVDF-BaTiO3 samples by 25% and 15% respectively.