摘要
Metal-deficient Zr nodes are constructed in UiO-66-NH 2 by vacuum treatment. • Zr-node microenvironment regulation enhances charge separation and O 2 activation. • UN 200/28 achieves 272.9 μmol g −1 h −1 H 2 O 2 production in pure water. • UN 200/28 delivers a 20-fold activity increase and 6.36% AQY at 420 nm. • H 2 O 2 formation follows an ORR-dominated pathway with secondary WOR contribution. Photocatalytic H 2 O 2 production from pure water and O 2 offers a sustainable route for green oxidant synthesis, yet its efficiency is limited by insufficient O 2 activation, sluggish charge separation, and poorly defined active sites. Herein, a metal-defect-engineered UiO-66-NH 2 photocatalyst is constructed through high-temperature vacuum treatment to regulate the Zr-node coordination microenvironment. The optimized UN 200/28 preserves the UiO-66-NH 2 crystalline framework and octahedral morphology, while a 7.8% decrease in Zr content is confirmed by ICP, STEM, FTIR, XPS and EPR, thereby indicating the formation of metal-deficient Zr nodes and the reconstruction of the local Zr O coordination microenvironment. These defect-induced structural modifications broaden visible-light absorption, narrow the band gap from 2.88 to 2.57 eV, and promote photogenerated charge separation and transfer. UN 200/28 exhibits markedly enhanced photocatalytic H 2 O 2 production in pure water under O 2 , achieving an H 2 O 2 formation rate of 272.9 μmol g −1 h −1 , a 20-fold improvement over pristine UiO-66-NH 2 , and an apparent quantum yield of 6.36% at 420 nm. The O 2 reduction and water oxidation processes account for approximately 63.2% and 36.8% of the total H 2 O 2 formation, respectively. This work demonstrates that cluster-level regulation of the Zr-node coordination microenvironment is an effective strategy for enhancing photocatalytic H 2 O 2 production in pure water. Download: Download high-res image (110KB) Download: Download full-size image
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