ZnIn2Se4 nanoparticles photocatalyst for efficient solar fuel production

Summary Selecting a suitable photocatalyst to establish the Z-scheme heterojunction which is accompanied by effective photogenerated hole and electron separation, is one of the advantageous strategies for efficient photocatalytic solar energy conversion. Therefore, we prepared a ZnIn2Se4 nanoparticles photocatalyst to build a double Z-scheme heterojunction with mixed-phase TiO2 nanofibers, boosting photocatalytic solar fuel preparation. The result of X-ray photoelectron spectroscopy confirmed the existence of interfacial chemical bonds and internal electric fields. The interfacial Ti-Se bond is regarded as a channel and the internal electric field serves as the driving force for electron transfer. And the composite photocatalyst exhibits a great hydrogen evolution rate of 0.11 mmol g−1 h−1. From a forward-working perspective, this work proposes a ZnIn2Se4 nanoparticles photocatalyst for efficient solar fuel conversion, promoting the application of bimetallic selenide photocatalyst in the field of photocatalysis.


Contents
Table S1.The energy dispersive X-ray spectroscopy (EDX) of ARTZ.Related to Figure 2. Table S2.The potential of AT, RT and ZISe.Related to Figure 3.

Figure S1 .
Figure S1.The details of synthesis method and crystal structure of photocatalyst.Related to Figure 1.(a) the preparation of photocatalysts, (b) the crystal structure of AT, RT and ZISe.

Figure S2 .
Figure S2.Comparison of XPS diffraction peaks spectra between ZISe and composite photocatalyst.Related to Figure 1.(a) The XPS spectra of Zn 2p, (b) the XPS spectra of In 3d for ZISe and ARTZ.

Figure S3 .
Figure S3.The morphology of ZISe and composite photocatalyst.Related to Figure 2. (a-b) The SEM image of ZnIn2Se4 NPs, (c-e) the EDS and elements mapping of Zn, In and Se, (f) the TEM image of ARTZ.

Figure S4 .
Figure S4.Lattice fringe diagram of composite photocatalyst ARTZ.Related to Figure 2. (a-b) the TEM image of ARTZ, (c) the HRTEM, IFFT and profile of IFFT images of AT, (d) the HRTEM, IFFT and profile of IFFT images of RT, (e) the HRTEM, IFFT and profile of IFFT images of ZISe.

Figure S5 .
Figure S5.Diagram of photocatalytic mechanism analysis with ISI-XPS.Related to Figure 4. (a) The mechanism of ISI-XPS, (b) the band structure of AT, RT and ZISe, (c) the establishment of internal electric field among AT, RT and ZISe, (d) electrons transfer mechanism of ARTZ composite under the light.

Figure S1 .
Figure S1.The details of synthesis method and crystal structure of photocatalyst.Related to Figure 1.(a) the preparation of photocatalysts, (b) the crystal structure of AT, RT and ZISe.

Figure S2 .
Figure S2.Comparison of XPS diffraction peaks spectra between ZISe and composite photocatalyst.Related to Figure 1.(a) The XPS spectra of Zn 2p, (b) the XPS spectra of In 3d for ZISe and ARTZ.

Figure S3 .
Figure S3.The morphology of ZISe and composite photocatalyst.Related to Figure 2. (a-b) The SEM image of ZnIn2Se4 NPs, (c-e) the EDS and elements mapping of Zn, In and Se, (f) the TEM image of ARTZ.

Figure S4 .
Figure S4.Lattice fringe diagram of composite photocatalyst ARTZ.Related to Figure 2. (a-b) the TEM image of ARTZ, (c) the HRTEM, IFFT and profile of IFFT images of AT, (d) the HRTEM, IFFT and profile of IFFT images of RT, (e) the HRTEM, IFFT and profile of IFFT images of ZISe.

Figure S5 .
Figure S5.Diagram of photocatalytic mechanism analysis with ISI-XPS.Related to Figure 4. (a) The mechanism of ISI-XPS, (b) the band structure of AT, RT and ZISe, (c) the establishment of internal electric field among AT, RT and ZISe, (d) electrons transfer mechanism of ARTZ composite under the light.

Figure S6 .
Figure S6.The photocatalytic CH4 evolution test over samples.Related to Figure 5.