Ice‐Assisted Synthesis of Black Phosphorus Nanosheets as a Metal‐Free Photocatalyst: 2D/2D Heterostructure for Broadband H2 Evolution. (9th May 2019)

• Record Type: Journal Article
• Authors: Zhang, Qingzhe; Huang, Shengyun; Deng, Jiujun; Gangadharan, Deepak Thrithamarassery; Yang, Fan; Xu, Zhenhe; Giorgi, Giacomo; Palummo, Maurizia; Chaker, Mohamed; Ma, Dongling
• Is Part Of: Advanced functional materials. Volume 29:Number 28(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-05-09
• Subjects: black phosphorous -- g‐C3N4 -- ice‐assisted exfoliation -- metal‐free photocatalysts -- photocatalytic H2 evolution; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201902486
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: A 2D/2D heterojunction of black phosphorous (BP)/graphitic carbon nitride (g‐C3 N4 ) is designed and synthesized for photocatalytic H2 evolution. The ice‐assisted exfoliation method developed herein for preparing BP nanosheets from bulk BP, leads to high yield of few‐layer BP nanosheets (≈6 layers on average) with large lateral size at reduced duration and power for liquid exfoliation. The combination of BP with g‐C3 N4 protects BP from oxidation and contributes to enhanced activity both under λ > 420 nm and λ > 475 nm light irradiation and to long‐term stability. The H2 production rate of BP/g‐C3 N4 (384.17 µmol g −1 h −1 ) is comparable to, and even surpasses that of the previously reported, precious metal‐loaded photocatalyst under λ > 420 nm light. The efficient charge transfer between BP and g‐C3 N4 (likely due to formed NP bonds) and broadened photon absorption (supported both experimentally and theoretically) contribute to the excellent photocatalytic performance. The possible mechanisms of H2 evolution under various forms of light irradiation is unveiled. This work presents a novel, facile method to prepare 2D nanomaterials and provides a successful paradigm for the design of metal‐free photocatalysts with improved charge‐carrier dynamics for renewable energy conversion. Abstract : A green and facile strategy is developed to generate few‐layer black phosphorus (BP): ice‐assisted exfoliation from bulk BP. A metal‐free photocatalyst is synthesized by combining BP and g‐C3 N4, which protects BP from oxidation and leads to efficient and broadband activity as well as long‐term stability in H2 evolution. Benefiting from formed NP bonds, the efficient charge transfer between them yields excellent photocatalytic performance.