Magnetic Fe3C@C nanoparticles as a novel cocatalyst for boosting visible-light-driven photocatalytic performance of g-C3N4.

In photocatalytic field, it is a significant challenge to synthesize cocatalyst with high performance, noble-metal free and facile methods to recycle. Herein, carbon layer coated Fe 3 C (Fe 3 C@C) nanoparticles were prepared by one-step method and for the first time utilized as highly efficient cocatalysts for improving visible-light-driven hydrogen evolution activity of g-C 3 N 4. The photocatalytic hydrogen evolution rate of optimal Fe 3 C@C/g-C 3 N 4 was about 27.2 times of bare g-C 3 N 4 samples. Furthermore, the Fe 3 C@C/g-C 3 N 4 composite catalyst showed excellent stability and reusability. The apparent quantum yield (AQY) of the optimized FeC@C/g- C 3 N 4 reaches 0.501% and 0.124% at 400 nm and 420 nm, respectively. The AQY of the FeC@C/g- C 3 N 4 is 26.2 times higher than that of g-C 3 N 4 at 400 nm Fe 3 C@C has an extraordinary cocatalytic effect for g-C 3 N 4 photocatalytic hydrogen evolution mainly due to three aspects: Firstly, the Fe 3 C acts as a trap to lure electrons because of its lower Fermi energy level and higher conductivity, which can increase the hydrogen production activity by trapping the photogenerated electrons produced by g-C 3 N 4 ; Secondly, the coated carbon layer can provide chemical protection for Fe 3 C nanoparticles and promote the transfer of photogenic electrons, thus further improving the efficiency and stability of photocatalytic hydrogen production; Thirdly, the strong magnetic property of Fe 3 C@C nanoparticles gives Fe 3 C@C/g-C 3 N 4 photocatalysts the advantages of low cost and high recovery efficiency. It is believed that this work provides a new strategy and possibility for the application of photocatalytic hydrogen production. • Carbon layer coated Fe 3 C (Fe 3 C@C) nanoparticles are prepared by one-step method. • The Fe 3 C@C as cocatalyst for boosting photocatalytic performance of g-C 3 N 4. • Fe 3 C@C/g-C 3 N 4 photocatalyst possesses strong magnetism and is easy to be recycled. • The Fe 3 C can efficiently trap the photogenerated electrons generated by g-C 3 N 4. • The carbon layer can provide chemical protection for Fe 3 C nanoparticles. [ABSTRACT FROM AUTHOR]