Energy-efficient and sustainable bromine recovery from e-waste via microdroplet-enhanced spray pyrolysis

Brominated flame retardants are widely used organic additives in modern electronic devices, but pose significant threat to human health and the environment after end of life. Efficiently dissociating C-Br bond and safely managing cleaved Br elements remain struggle to currently available methods such as landfill, incineration, leaching, and pyrolysis. Here, we report a two-step spray pyrolysis of electronic waste for simultaneous C-Br cleavage and Br upcycling. First, the spray of neutral water generates oppositely charged microdroplets, which enrich brominated flame retardants on the gas-liquid interface and then trigger effective C-Br bond activation mediated by the inter-microdroplets electric field under 400 °C pyrolysis. This enables the efficient bromine fixation on nano‑iron surface through an unprecedented process more cost-effective than industrial bromine production, in the second pyrolysis step. The bromine is ultimately recovered as inorganic bromine ferrous bromide (FeBr₂) with a yield of ~80 %. The strategy transforms hazardous bromine waste into a sustainable bromine resource, thus providing a new incentive for e-waste recycling.