Visible‐light‐driven Ni 3 FeN/g‐C 3 N 4 Z‐scheme heterostructure for remarkable photocatalytic water splitting

Abstract It is very essential to grow efficient and abundant photocatalysts for overall water cracking to produce hydrogen. Ni 3 FeN nanosheets were synthesized by combining simple sol–gel and calcining methods using urea as nitrogen source. A heterostructure was constructed between Ni 3 FeN and g‐C 3 N 4 to enhance the absorption capacity of visible light. The reformed Z‐scheme Ni 3 FeN/g‐C 3 N 4 heterojunction exhibited an excellent visible‐light photocatalytic activity. The average hydrogen evolution rate of 5 wt% Ni 3 FeN/g‐C 3 N 4 composite is 528.7 μmol h −1 g −1 due to the Z‐scheme Ni 3 FeN/g‐C 3 N 4 junction, which promotes the separation of photogenerated e − /h + . Interestingly, the average H 2 production of Ni 3 FeN/g‐C 3 N 4 is nearly 8.3 and 3.6 times higher than that of Fe 4 N/g‐C 3 N 4 and Ni 4 N/g‐C 3 N 4 , respectively, indicating that bimetallic nitrides as cocatalysts are more conducive to enhancing the performance of photocatalysts. Importantly, the Ni 3 FeN/g‐C 3 N 4 composite exhibited good cycle stability, and the hydrogen production performance hardly changed after four cycle experiments. Furthermore, photoluminescence, electrochemical impedance spectroscopy, and transient photocurrent response show that Ni 3 FeN/g‐C 3 N 4 heterojunction improves the separation efficiency of photoinduced e − /h + . This work provides a feasibility of the cocatalyst Ni 3 FeN for use in photocatalytic hydrogen production.