Construction photothermal/pyroelectric property of hollow FeS2/Bi2S3 nanostructure with enhanced full spectrum photocatalytic activity

In order to take full advantage of solar energy, the development of full spectrum photocatalysts have become focus of attention. Herein, the hollow FeS2/Bi2S3 is constructed to enhance photocatalytic hydrogen evolution by the synergistic effect of photothermal property and thermoelectric effect. This is the first time to exploit the ΔT between the heat generated by photothermal effect and the cold photocatalytic system to provide driving force for pyroelectric effect. The FeS2 can make the most of near infrared (NIR) light to thermogenesis and provide hot end for thermoelectric effect of Bi2S3. Under the environment of circulating condensed water, Bi2S3 will cause spontaneous polarization and generate thermoelectric effect under the influence of temperature difference (ΔT) fluctuation. It releases the charge on the surface, so as to control the migration direction and rate of carriers in FeS2 nanoparticles. The results of surface work function and COMSOL numerical simulation display that the improvement of photocatalytic efficiency is on account of the lower surface work function and high pyroelectric potential. The hydrogen production efficiency of FeS2/Bi2S3-3 reaches 16.8 mmol g−1 h−1 and has favourable cycle stability. This study provides a new insight for the design and construction of novel full spectrum photocatalysts.