Ni-Fe-WSx polynary hollow nanoboxes as promising electrode catalysts for high-efficiency triiodide reduction in dye-sensitized solar cells

Hollow functional materials with adjustable morphologies based on transition metal sulfides have been considered as a class of attractive and promising electrocatalysts for multifarious energy conversion devices. Herein, we adopt a facile template-engaged method to synthesize morphology-tunable Ni-Fe-WSx hollow nanoboxes by changing the mass ratios (1/1, 1/2 and 1/3) of nickel iron Prussian-blue analog precursors and (NH4)(2)WS4. During the above processes, (NH4)(2)WS4 acted as a multifunctional vulcanizator to supply elements of S and W simultaneously and the surface of Ni-Fe-WSx nanoboxes became rougher with the increment of WS42-. Noteworthy, profiting to the moderated surface morphology, appropriate doped ratio and the synergistic effect of multiple elements, Ni-Fe-WSx-2 hollow nanoboxes not only possessed higher specific surface and well-defined interior voids but also performed excellent catalytic properties on promoting the reduction of l3 comparing to Ni-Fe-WSx-1, Ni-Fe-WSx-3 and Ni-Fe-S in dye-sensitized solar cells (DSSCs). As expected, the DSSC prepared with a Ni-Fe-WSx-2 counter electrode (CE) possessed a higher value of power conversion efficiency (PCE) about 9.86% which was more remarkable than that of Pt (8.20%). (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

A facile template-engaged method was used to synthesize morphology-tunable Ni-Fe-WSx hollow nanoboxes, resulting in rougher surfaces and excellent catalytic properties in DSSCs, with Ni-Fe-WSx-2 exhibiting the highest power conversion efficiency compared to other samples and Pt.