Autonomous Solar Metallurgy for High-Purity Gold Recovery from Electronic Waste

Sustainable recovery of precious metals from electronic waste is constrained by the difficulty of integrating rapid capture, complete reduction, and product separation without external reagents or energy-intensive inputs. Here, we report a bioinspired, defect-encoded solar metallurgical platform based on copper sulfide (Cu₃₁S₁₆) that couples light harvesting, photothermal conversion, and intrinsic redox functionality. Copper-vacancy-induced mid-gap states enhance broadband solar absorption, localized thermal amplification, and photoexcited charge generation, while soft sulfide coordination sites selectively bind Au(III). This co-localized photothermal-photochemical coupling accelerates interfacial transport and complete multielectron reduction to Au(0), and uniquely triggers a light-sustained nucleation-growth process that culminates in spontaneous self-abscission of millimetre-scale, high-purity gold. The integrated mechanism overcomes site-saturation, delivering an ultrahigh uptake capacity of 6274 mg g^-1, near-instantaneous kinetics (>95% removal within 15 s), near-unity selectivity (K_d = 2.5 × 10⁷ mL g^-1), and wide pH range operation. Continuous-flow processing of authentic leachates sustains gold recovery for 65 h and yields ∼24 K gold, demonstrating techno-economic viability with ∼95% reductions in energy, chemical, and carbon footprints relative to conventional routes. By unifying energy conversion, reaction, and separation into one solar-driven process, this work establishes a self-powered, self-separating metallurgical paradigm for low-carbon recovery of precious and critical metals.