SiP Nanosheets: A Metal-Free Two-Dimensional Photocatalyst for Visible-Light Photocatalytic H₂ Production and Nitrogen Fixation

Abstract

Two-dimensional (2D) semiconductors for photocatalysis are more advantageous than the other photocatalytic materials since the 2D semiconductors generally have large specific surface area and abundant active sites. Phosphorus silicon (SiP), with an indirect bandgap in bulk and a direct bandgap in the monolayer, has recently emerged as an attractive 2D material because of its anisotropic layered structure, tunable bandgap, and high charge carrier mobility. However, the utilization of SiP as a photocatalyst for photocatalysis has been scarcely studied experimentally. Herein, we reported the synthesis of SiP nanosheets (SiP NSs) prepared from bulk SiP by an ultrasound-assisted liquid-phase exfoliation approach which can act as a metal-free, efficient, and visible-light-responsive photocatalyst for photocatalytic H2 production and nitrogen fixation. In a half-reaction system, the maximal H2 and NH3 generation rate under visible light irradiation achieves 528 and 35 μmol·h–1·g–1, respectively. Additionally, the apparent quantum yield for H2 production at 420 nm reaches 3.56%. Furthermore, a Z-scheme photocatalytic overall water-splitting system was successfully constructed by using Pt-loaded SiP NSs as the H2-evolving photocatalyst, Co3O4/BiVO4 as the O2-evolving photocatalyst, and Co­(bpy)3 3+/2+ as an electron mediator. Notably, the highest H2 and O2 generation rate with respect to Pt/SiP NSs achieves 71 and 31 μmol·h–1·g–1, respectively. This study explores the potential application of 2D SiP as a metal-free visible-light-responsive photocatalyst for photocatalysis.

Atomic‐Level Regulated 2D ReSe2: A Universal Platform Boostin Photocatalysis

“…This could arise from generation of defects in ReSe 2 NSs during exfoliation of bulk ReSe 2 . [ 5 ] As shown in Table S1 (Supporting Information), bulk ReSe 2 shows the Se/Re atomic ratios of 1.852 and 1.516, based on inductively coupled plasma atomic emission spectroscopy (ICP‐AES) and energy‐dispersive X‐ray spectroscopy (EDS), respectively. These results indicate the existence of Se vacancies in bulk ReSe 2 .…”

Sub-10 nm anatase TiO2 nanoparticles for rapid photocatalytic H2 production from lignocellulosic biomass

“…Thus, the CB level was located at −0.21 V vs. RHE since the CB level position was more negative by 0.2 eV than its flat band potential. 44 The CB level of TiO 2 is more negative than the redox potential of H + /H 2 (0 V vs. RHE), 45 providing a driving force for H 2 generation. Because the TiO 2 -3 has a bandgap of 3.20 eV (Fig.…”

Ammonia Electrosynthesis with a Stable Metal‐Free 2D Silicon Phosphide Catalyst

“…[ 34 ] As for the P 2p XPS spectrum shown in Figure 1c, the signals are fitted into the typical 2p 1/2 and 2p 3/2 peaks of SiP. [ 35 ] It is noted that the oxidized phosphorus peak as 132.7 eV is weak, [ 36,37 ] suggesting good chemical stability of as‐obtained C‐SiP NSs. The powder was able to stabilize in air for two years without any color change (Figure S3, Supporting Information), which generally could not be realized by other phosphorous‐based materials, such as black phosphorous.…”