LAUSR

Nitrate and formaldehyde, which are substantial wastes in industrial and agricultural effluents, pose significant hazards to the human health and ecosystem. Current purification technologies remain great challenges due to the unsatisfactory energy‐intensive, time‐consuming and noticeably costly reasons. Herein, a bifunctional electrocatalysts of Pd single‐atoms doped Cu3P quantum dots (Pd‐Cu3P SA‐QDs) are reported to moderately optimize the H* sorption behaviors for accelerating the kinetics of nitrate reduction (NO3RR) and formaldehyde oxidation (FOR) reactions in a dual‐directional way, thus realizing the high activity and selectivity for both cathodic ammonia (NH3) synthesis and anodic H2 production concurrently. Specifically, a very positive onset potential of +0.36 V (versus RHE) is recorded for NO3RR with a high faradaic efficiency (FE) of 99 % for NH3 at −0.3V (versus RHE), while the FOR can be initialized at a very low onset potential of −0.07 V (versus RHE) with > 90 % FE for formate and > 95 % FE for H2 at 0.3 V (versus RHE). Notably, a self‐powered galvanic system can be triggered by integrating the above two electrode‐based reactions, thus exhibiting an open‐circuit voltage of 0.892 V, a peak power density of 12.1 mW cm−2, and capable of generating 8.8 KWh kg−1 of electrical energy.