Phosphorene nanosheet decorated graphitic carbon nitride nanofiber for photoelectrochemically enhanced hydrogen evolution from water splitting

Background: Phosphorene nanosheet is a p-type semiconductor with excellent optoelectronic property and large surface area, while graphitic carbon nitride (g-C3N4) nanofiber is a n-type visible-light-driven photocatalyst. The fabrication of p-n heterostructured nanocomposites for hydrogen evolution from water splitting via photo -electrochemistry is an exceptionally promising technique. Method: Phosphorene and g-C3N4 were prepared by electrospinning and ultrasonic exfoliation procedures, respectively, and then mixed physically by Van deer Waal force to form the p-n heterojunction. The photo -electrochemical hydrogen evolution from water splitting was performed under solar light irradiation. Significant findings: The morphological analysis show that 100-200 nm phosphorene nanosheets are successfully decorated on 450-nm g-C3N4 nanofibers. After adding 4-18 wt% phosphorene onto g-C3N4 nanofiber (P/CN), the specific surface area of P/CN nanocomposites is in the range of 52.1-68.3 m2 g-1. The addition of 13 wt% phosphorene is optimal for P/CN nanocomposite to maximize the hydrogen evolution rate of 2,208 mu mol h-1 g-1 by accelerating the electron transfer to enhance the PEC performance in P/CN heterostructure under illumina-tion. Results have signified that the metal-free P/CN photocatalyst can provide an effective solar-light-responsive capability toward water splitting, which can create a promising strategy to fabricate low-dimensional electrode materials for a wide variety of water-energy nexus and green energy applications.