Correlating electrocatalytic activities with sulfur species on sulfur-doped cobalt oxide

Abstract

Metal chalcogenide related materials have demonstrated outstanding catalytic activities for numerous chemical reactions in energy conversion devices. However, the actual active species have not yet been fully identified, especially for triiodide reduction in dye-sensitized solar cells (DSSCs). We herein adopted a vapor-phase hydrothermal (VPH) approach to controllably create the sulfur dopants on the Co 3 O 4 nanosheets surface for high-performance DSSCs with a best power conversion efficiency (PCE) of 8.86%. More importantly, our XPS and electrochemical analysis confirm a close correlation between the S 2species and the electrocatalytic activities.

In Situ Reconstruction to Surface Sulfide Adsorbed Metal Scaffold for Enhanced Electrocatalytic Hydrogen Evolution Activity

“…X‐ray photoelectron spectroscopy (XPS) measurements (Figure S7, Supporting Information) imply the successful doping of S 2− anion, which agrees well with the previous reports. [ 12,13 ] Furthermore, when comparing to the Co 2p XPS spectra of Co 3 O 4 /CC, obvious shifts of Co 2p 3/2 peaks towards the lower binding energies can be observed for S‐Co 3 O 4 /CC (Figure 1e). Meanwhile, S‐Co 3 O 4 /CC has an insignificant contribution of lattice O 2− according to the O 1s XPS spectra (Figure 1e), demonstrating the presence of plentiful anion vacancies.…”

“…S‐Co 3 O 4 /CC was fabricated via H 2 S‐involved vapor phase hydrothermal (H 2 S‐VPH) method. [ 12 ] Typically, Co 3 O 4 nanosheets on carbon cloth (Co 3 O 4 /CC) were first prepared by annealing the electrodeposited Co(OH) 2 nanosheets in air. H 2 S‐VPH was then conducted in a Teflon‐lined autoclave reactor at 140 °C using Al 2 S 3 as the precursor of H 2 S. The topotactic transformation involving partial anion replacement and vacancies creation thus induces the evolution of coordination geometry of Co atoms in Co 3 O 4 as illustrated in Figure 1 a.…”

Engineering of anchor sites and reaction time to efficiently synthesize high loading and stable sub-nanocluster catalysts

“…After determining that the presence of functional groups has a significant impact on the size of the material, we extend the range of functional groups to N and N, S bifunctional groups using melamine and thiourea as precursors (denoted as Pt 0.6 / KB-O M5 -40 and Pt 0.6 /KB-O S5 -40) to investigate the effects of different functional groups on the structure and catalytic properties of the materials. 3,11,33,34 Melamine and thiourea were selected as the precursor to provide N and N, S bifunctional groups, and these catalysts were synthesized using the same synthesis method. As can be seen from the Fig.…”