Construction of the Z-Scheme Heterogeneous HKUST-1/BiVO₄ Nanorod Composite for Enhanced Piezo-Photocatalytic Reduction Performance of Cr(VI)

In recent years, piezo-photocatalysis has become a promising strategy for solving environmental pollution problems by adding additional mechanical energy to the photocatalysis process. This work reported the effective synthesis of a variety of HKUST-1/BiVO₄ heterogeneous materials by combining monoclinic BiVO₄ and porous HKUST-1 semiconductors. The piezo-photocatalytic properties of HKUST-1/BiVO₄ were studied by the reduction of hexavalent chromium (Cr(VI)) under visible-light irradiation and ultrasonic waves. In the piezo-photocatalysis process, the best reduction rates among as-prepared HKUST-1/BiVO₄ composites were up to 96.20% of 10 ppm Cr(VI) solution, which was approximately 1.80 times that under visible light and about 4.13 times that under ultrasound. Under the action of the piezoelectric potential, the availability of free radicals increased the reduction rate of Cr(VI) and reached a synergistic effect of 1.14-fold.