Controllable synthesis of coloured Ag⁰/AgCl with spectral analysis for photocatalysis

Broad spectrum absorption of semiconductor photocatalysts is an essential requirement to achieve the best values of solar energy utilization. Here, through precise surface state adjustment, coaxial tri-cubic Ag⁰/AgCl materials with distinct apparent colours (blue and fuchsia) were successfully fabricated. The reasons for the different colour generation of the Ag⁰/AgCl materials were investigated by performing corresponding spectrum analysis. It was revealed that Ag⁰/AgCl-blue and Ag⁰/AgCl-fuchsia crystals could efficiently boost the photon energy harvesting, spanning from the UV to near-infrared spectral region (250-800 nm), and achieved 2.6 and 5.4 times the wastewater degradation efficiency of AgCl-white. Simultaneously, these two fresh coloured candidates were demonstrated to have preferable photocatalytic CO₂ photoreduction capability, with yields of ∼3.6 (Ag⁰/AgCl-fuchsia) and 2.6 (Ag⁰/AgCl-blue) times that of AgCl-white. It is expected that this work will provide a beneficial perspective for understanding the solar absorption feature at both the major structure modulation and particular surface state regulation level.