Novel synthesis strategy for Z-scheme BiOCl/UiO-66 photocatalyst: Enhanced surface area and improved Cr(VI) removal efficiency

MOF-based photocatalysts with a large specific surface area have been proven to be a potential candidate for removing heavy metal contaminants from the water environment. Herein, we present a much more available Z-scheme BiOCl/UiO-66 composite photocatalyst via a one-step hydrothermal method for efficiently removing Cr (VI) from wastewater. More importantly, when adding bismuth nitrate in the synthesis procedure, BiOCl was in situ generated on the surface of UiO-66 without an additional chlorine source. Experimental results showed that this novel photocatalyst could effectively remove Cr(VI) without adjusting the pH value and adding hole or hydroxyl radical scavengers, which is meant for practical application. Besides, the BET surface area of one-step synthesized BiOCl/UiO-66 composite was considerably extended to 1530.82 m2/g, which is larger than that of two-step synthesized BiOCl/UiO-66 composite and bare UiO-66. Characterization results verified that this one -step synthesized composite's outstanding Cr(VI) photo-removal efficiency was ascribed to increased active sites and improved charge separation and transfer efficiency. This study will likely to provide an effective way to simplify the synthesis procedure of bismuth materials/MOF composites with excellent applications.

Automated summary

A one-step hydrothermal method was used to synthesize a BiOCl/UiO-66 composite photocatalyst, which showed high efficiency in removing Cr(VI) from wastewater without adjusting the pH value and adding hole or hydroxyl radical scavengers. The composite also exhibited an extended surface area, increased active sites and improved charge separation and transfer efficiency.