N-doped WO 3 anchored on porous carbon as boosted oxygen reduction catalyst for zinc-air batteries.

N-doped WO 3 anchored on porous carbon (N-WO 3 /PNC) was synthesized as an efficient oxygen reduction catalyst. The N doping reduced the overpotential of WO 3 during oxygen reduction. N-WO 3 /PNC displayed a half-wave potential of 0.85 V. An N-WO 3 /PNC-based zinc-air battery displayed a high power density of 209.7 mW cm -2 .