Ni7S6 decorated g-C3N4/graphene oxide composites for enhanced visible light photocatalytic hydrogen evolution.

Rationally designing high-efficient g-C 3 N 4 based photocatalysts still remains a big challenge. Herein, Ni 7 S 6 decorated K-doped g-C 3 N 4 /graphene oxide photocatalyst was synthesized. Interestingly, amorphous conductive carbon black and urea are simultaneously transferred to graphene oxide and K-doped g-C 3 N 4 , which achieves in-situ coupled K-g-C 3 N 4 /graphene oxide composite. The in-situ fabricated graphene oxide acts as a charge transfer substrate for the rapid photocarriers migration. Ni 7 S 6 forms Schottky heterojunction with K-g-C 3 N 4 photocatalyst, promoting photocarriers separation. The Ni 7 S 6 /K-g-C 3 N 4 /graphene oxide composite achieves a visible light hydrogen production rate of 487.59 μmol·g−1·h−1, which is about 7.5 times higher than that of K-g-C 3 N 4 (65.4 μmol·g−1·h−1). This work provides a novel strategy for preparing high-efficient g-C 3 N 4 based photocatalysts. [Display omitted] • Graphitic carbon nitride modified with graphene oxide and Ni 7 S 6 was prepared. • Graphitization and K-g-C 3 N 4 formation simultaneously took place forming tightly coupled interface. • Ni 7 S 6 with K-g-C 3 N 4 formed Schottky junction to inhibit the recombination of photocarriers. • The composite shows an excellent photocatalytic activity of 487.59 μmol·g−1·h−1 and enhanced stability. [ABSTRACT FROM AUTHOR]