Visible‐light‐driven Ni3FeN/g‐C3N4 Z‐scheme heterostructure for remarkable photocatalytic water splitting

Abstract

AbstractIt is very essential to grow efficient and abundant photocatalysts for overall water cracking to produce hydrogen. Ni3FeN nanosheets were synthesized by combining simple sol–gel and calcining methods using urea as nitrogen source. A heterostructure was constructed between Ni3FeN and g‐C3N4 to enhance the absorption capacity of visible light. The reformed Z‐scheme Ni3FeN/g‐C3N4 heterojunction exhibited an excellent visible‐light photocatalytic activity. The average hydrogen evolution rate of 5 wt% Ni3FeN/g‐C3N4 composite is 528.7 μmol h−1 g−1 due to the Z‐scheme Ni3FeN/g‐C3N4 junction, which promotes the separation of photogenerated e−/h+. Interestingly, the average H2 production of Ni3FeN/g‐C3N4 is nearly 8.3 and 3.6 times higher than that of Fe4N/g‐C3N4 and Ni4N/g‐C3N4, respectively, indicating that bimetallic nitrides as cocatalysts are more conducive to enhancing the performance of photocatalysts. Importantly, the Ni3FeN/g‐C3N4 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 Ni3FeN/g‐C3N4 heterojunction improves the separation efficiency of photoinduced e−/h+. This work provides a feasibility of the cocatalyst Ni3FeN for use in photocatalytic hydrogen production.