Anode for Nanoparticles, Cathode for Alloy: A Dual‐Functional Electrochemical Strategy for Spent ITO Upcycling

Abstract

ABSTRACT The production and disposal of indium tin oxide (ITO) targets are rapidly increasing with the expansion of cutting‐edge optoelectronic and display technologies. To reduce reliance on indium (In) resources, there is an urgent need to develop efficient recycling strategies for spent ITO (s‐ITO). Here, we propose a facile electrochemical recovery approach in which s‐ITO serves as both the anode and cathode in Na 2 SO 4 solution. This dual‐function system enables selective anode conversion of s‐ITO into nanoscale Sn‐doped In 2 O 3 particles and cathode electro‐deoxidation into an In–Sn alloy, delivering an overall current‐utilization efficiency exceeding “120%.” Combined experiments and density functional theory (DFT) reveal fundamentally differentiated electrode pathways: anodic conversion proceeds through lattice oxygen mechanism (LOM) deconstruction with oxygen‐vacancy formation and structural destabilization, whereas cathodic recovery is governed by oxygen removal and in situ alloying. The process remains stable under 150 A scale‐up electrolysis over eight cycles, with the anode enabling parallel recovery and the cathode enabling recovery toward the In–Sn alloy. These findings establish a mechanism‐informed, acid‐free, and dual‐functional route for the closed‐loop upcycling of s‐ITO.