2D Layered Bimetallic Phosphorous Trisulfides M^IM^IIIP₂S₆ (M^I = Cu, Ag; M^III = Sc, V, Cr, In) for Electrochemical Energy Conversion

Abstract

conversion and storage systems in which electrocatalytic water splitting reactions are included. [1] Hydrogen production from water electrolysis is considered a sustainable alternative since its by-product is water, but the biggest challenge in the development of electrocatalysts remains in overcoming the reaction kinetics of hydrogen evolution reaction (HER), especially in alkaline electrolytes due to additional water dissociation step which requires high overpotentials to initiate the catalysis. [2][3][4] Noble metals such as platinum, ruthenium, or iridium are conventional and satisfactory catalysts for water splitting reactions, however, their scarcity and high cost are limitations in large-scale production which has conducted intensive research to find more accessible materials to replace such precious metals. In the vast diversity of investigated materials, 2D materials have been reported as candidates for HER due to their tunable and uniformly exposed lattice planes and unique electronic state, [5,6] and among them, metal phosphorous trichalcogenides (MPX 3 ) have emerged as promising electrocatalysts. [7][8][9] Their general chemical formula is M II 2 [P 2 X 6 ] 4− , with the additional mixed metal configurations of M I 2 M II [P 2 X 6 ] 4− , and M I M III [P 2 X 6 ] 4− being possible, where X = S, Se, and in which metal cations stabilize a thiophosphate [P 2 S 6 ] 4− or selenophosphate [P 2 Se 6 ] 4− anionic framework forming layers that are weakly bonded together through van der Waals interactions. [8] Great progress has been achieved with M II 2 [P 2 X 6 ] 4− , or MPX 3 in its simplified formula, as HER electrocatalysts in alkaline media with reports on FePS 3 , [10] NiPS 3 , [11] and MnPX 3 . [12] Still in the HER region, the MPX 3 have also revealed significant enhancement for photocatalytic water splitting but the research trends remain on Fe-, [13,14] Mn-, [14,15] Cd-, [14] and ZnPX 3 [14] materials. Reports on Ni- [14] or MgPX 3 [16] materials are also found. So, all these works opened a new avenue for MPX 3 electrocatalysts thus raising interest in replacing the divalent metal with univalent and trivalent metals to investigate the catalytic performance of layered M I M III P 2 X 6 structures. A stable photoelectrochemical HER has been reported for CuInP 2 S 6 [17,18] and Ag 0.5 In 0.5 P 2 X 6 [14] compounds; however, HER in alkaline mediaConsiderable improvements in the electrocatalytic activity of 2D metal phosphorous trichalcogenides (M 2 P 2 X 6 ) have been achieved for water electrolysis, mostly with M II 2 [P 2 X 6 ] 4− as catalysts for hydrogen evolution reaction (HER). Herein, M I M III P 2 S 6 (M I = Cu, Ag; M III = Sc, V, Cr, In) are synthesized and tested for the first time as electrocatalysts in alkaline media, towards oxygen reduction reaction (ORR) and HER. AgScP 2 S 6 follows a 4 e − pathway for the ORR at 0.74 V versus reversible hydrogen electrode; CuScP 2 S 6 is active for HER, exhibiting an overpotential of 407 mV and a Tafel slope of 90 mV dec −1 . Density functional theory mod...

Comparative Effects of Hydrazine and Thermal Reduction Methods on Electromagnetic Interference Shielding Characteristics in Foamed Titanium Carbonitride MXene Films

“…Particularly, Foaming stands out as one of the most efficient methods in the large‐scale fabrication of MXene‐based EMI shielding materials, especially in industrial sectors where weight reduction is essential, such as aircraft and portable electronic devices. [ 78 ] These emphases facilitate the large‐scale preparation of robust and highly effective MXene shields at the commercial scale.…”

Direct reduction of diluted CO2 gas to C2 products by copper hydroxyphosphate microrods

“…These heteroatom dopant in copper or copper oxide help achieve the formation of Cu δ+ , which strengthens the strong adsorption capacity of *CO intermediates, and ultimately facilitates the formation of C 2 products 25 . Among all these inorganic ions, phosphorous anion is widely studied in electrocatalysis such as hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction and carbon dioxide reduction reaction 26–28 . Our previous study has proved PO 4 3− are able to help maintain the oxidation state of silver and facilitate *CO generation 29 .…”

“…25 Among all these inorganic ions, phosphorous anion is widely studied in electrocatalysis such as hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction and carbon dioxide reduction reaction. [26][27][28] Our previous study has proved PO 4 3À are able to help maintain the oxidation state of silver and facilitate *CO generation. 29 The introduction of phosphorous anion in copper-based materials perhaps play a difference on diluted CO 2 reduction to C 2 products.…”

A Smart Amorphous Wire Composite with Tunable Electromagnetic Shielding

“…[8][9][10][11][12][13][14] However, creating easy and clever EMI shields with exceptional and adjustable shielding performance still proves to be difficult. [15][16][17] Especially smart EMI shields with "On/Off" switchable shielding capability (i.e., the SE value is close to 0 dB in the "Off" state and greater than 20 dB in the "On" state, switching between EM transmission and effective shielding) are seldom reported.…”