Monodisperse Ultrasmall Manganese-Doped Multimetallic Oxysulfide Nanoparticles as Highly Efficient Oxygen Reduction Electrocatalyst

Abstract

The highly efficient and cheap non-Pt-based electrocatalysts such as transition-based catalysts prepared via facile methods for oxygen reduction reaction (ORR) are desirable for large-scale practical industry applications in energy conversion and storage systems. Herein, we report a straightforward top-down synthesis of monodisperse ultrasmall manganese-doped multimetallic (ZnGe) oxysulfide nanoparticles (NPs) as an efficient ORR electrocatalyst by simple ultrasonic treatment of the Mn-doped Zn-Ge-S chalcogenidometalate crystal precursors in HO/EtOH for only 1 h at room temperature. Thus obtained ultrasmall monodisperse Mn-doped oxysulfide NPs with ultralow Mn loading level (3.92 wt %) not only exhibit comparable onset and half-wave potential (0.92 and 0.86 V vs reversible hydrogen electrode, respectively) to the commercial 20 wt % Pt/C but also exceptionally high metal mass activity (189 mA/mg at 0.8 V) and good methanol tolerance. A combination of transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and electrochemical analysis demonstrated that the homogenous distribution of a large amount of Mn(III) on the surface of NPs mainly accounts for the high ORR activity. We believe that this simple synthesis of Mn-doped multimetallic (ZnGe) oxysulfide NPs derived from chalcogenidometalates will open a new route to explore the utilization of discrete-cluster-based chalcogenidometalates as novel non-Pt electrocatalysts for energy applications and provide a facile way to realize the effective reduction of the amount of catalyst while keeping desired catalytic performances.

Direct observation of charge transfer between molecular heterojunctions based on inorganic semiconductor clusters

“…[27][28][29][30][31][32] Recently, discrete clusters with uniform size and atomically precise crystal lattice structure have been successfully dispersed into cluster-based quantum-dotlike nanoparticles (also called supraclusters) in solvents, and correlations between the cluster structure and function (such as electrochemical, photocatalytic and photoelectric applications) have been established. [33][34][35][36][37] Although the roles of clusters in crystalline open frameworks remain unclear, the signicance of clusters in these frameworks seems to extend beyond the beauty of a symmetrical structure and apparent functionality as nodes for open framework construction. For example, precise doping of clusters at the atomic scale allows one to study the synergistic effect of framework heteroatoms on photoluminescence and electrocatalytic properties.…”

Shining Light on Anion-Mixed Nanocatalysts for Efficient Water Electrolysis: Fundamentals, Progress, and Perspectives

“…To date, a wide range of TM compounds with oxysulfides, e.g., (CoNi)O x S y , Si-MWs@MoO x S y , CoO 0.87 S 0.13 /GN, Ni y Co 1−y O x S z , and Mn(Zn, Ge) oxysulfide [8,130,131], have been explored as a catalyst for electrochemical applications such as supercapacitors [132], PEC [130], Zn-air batteries [133], PEMWE [134] and ORR [135]. Subsequently, Suntivich's group investigated a partial S anionic substitution in CoO NPs to increase the H 2 evolution [50].…”

“…The O and S derived from the same VIA group of the periodic table are easily mixed to modify the compounds. To date, a wide range of TM compounds with oxysulfides, e.g., (CoNi)O x S y , Si-MWs@MoO x S y , CoO 0.87 S 0.13 /GN, Ni y Co 1− y O x S z , and Mn(Zn, Ge) oxysulfide [ 8 , 130 , 131 ], have been explored as a catalyst for electrochemical applications such as supercapacitors [ 132 ], PEC [ 130 ], Zn-air batteries [ 133 ], PEMWE [ 134 ] and ORR [ 135 ].…”

Ionothermal Access to Defined Oligomers of Supertetrahedral Selenido Germanate Clusters

“…In order to fabricate functional nanomaterials, e.g., for optoelectronic devices, by processing such supertetrahedral clusters, there has been an increasing interest in dissolving such materials in common solvents. 19 However, only a few studies about dissolving ligand-free clusters have been reported, and most of them required the use of highly polar solvents like water or methanol owing to the relatively strong electrostatic interactions between anionic clusters and cationic counterions. 20 Therefore, it is significant and at the same time challenging to alleviate the above-mentioned electrostatic interactions, for a corresponding extension of the applications of materials based on supertetrahedral chalcogenido (semi)metalate units.…”