Sacrificial template induced Fe-, N-, and S-tridoped hollow carbon sphere as a highly efficient electrocatalyst for oxygen reduction reaction

•Hollow-structured FeNSC was synthesized using impregnation and pyrolysis method assisted by sacrificial SiO2 template.•The unique hollow architecture and tri-doping strategy led to outstanding ORR performance.•The FeNSC indicated remarkable half-wave potential (0.877 V vs. RHE) and long-term durability (over 100 h).