Engineering Heteroatomic Nanotraps in Vinyl‐Benzazole COFs: Record Capacity and 99% Selectivity for Photocatalytic Gold Recovery From E‐Waste

Abstract

ABSTRACT The recovery of gold from electronic waste is a critical environmental and technological challenge for a circular and sustainable economy. Conventional methods for gold recovery often suffer from low efficiency, poor selectivity, and reliance on harsh chemicals. In this work, we engineered three vinyl‐azole‐bridged covalent organic frameworks (COFs), systematically controlling heteroatom motifs to elucidate the structure‐activity relationships behind gold ion adsorption and photocatalytic reduction. This strategic incorporation of azole‐based units yielded hydrogen‐bonded nanotraps along the pore walls, thereby maximizing active‐site density and enhancing electrostatic interactions for the selective capture of gold ions. We found that all these COFs show gold adsorption capacities exceeding 3600 mg g − 1 , with the thiazole‐containing COF—featuring both nitrogen and sulfur—exhibiting the highest binding affinity and photocatalytic efficiency to a record value of 4658.1 mg g − 1 under optimal conditions and a 99.2% efficiency for gold extraction. These results are confirmed by density functional theory (DFT) calculations, x‐ray photoelectron spectroscopy, and real e‐waste recovery experiments. The highly conjugated framework facilitates synergistic photoreduction of Au(III) to Au(0), exploiting the unique interplay between heteroatom chemistry, microenvironment engineering, and light‐driven redox processes. This work introduces a new class of COF photocatalysts engineered with heteroatomic nanotraps, achieving exceptional gold recovery efficiency.