Subsurface oxygen reduction reaction activity on Ti₂N MXene revealed byin situRaman spectroelectrochemistry

Abstract

Pt-based catalysts are generally used for the oxygen reduction reaction (ORR) in batteries and fuel cells but due to their high price, low abundance, and poor stability, alternative materials are...

Switchable Charge Storage Mechanism via in Situ Activation of MXene Enables High Capacitance and Stability in Aqueous Electrolytes

“…The broad and predominant peaks that emerge at 3300 and 1400 cm –1 are assigned to the vibrational stretching and bending of the OH group. The peak at 1600 cm –1 indicates N–H bonding resulting from the sublattice N atoms being exposed during acid washing . SEM was employed to investigate the morphology, completion of the etching process, and structural defects of both the Ti 4 AlN 3 MAX (Figure S2a) and the multilayer Ti 4 N 3 T x MXene (Figure d).…”

“…About 0.5 g of the etched Ti 4 AlN 3 -MST was ground and acid-washed by mixing with 20 mL of 4 M formic acid (Sigma-Aldrich, 95%) in a beaker similar to previous synthesis work with Ti 2 NT x . , The beaker contents were stirred for 1 h at 500 rpm using a Teflon-lined stir bar. The resulting solution was then membrane-filtered onto a 0.10 μm polycarbonate membrane (Whatman Nucleopore) and washed continuously by adding deionized water (18.2 MΩ cm, Milli-Q) until a pH of 6 was attained.…”

Investigation of the Vibrational Properties of 2D Titanium Nitride MXene Using DFT

“…17 Another related experimental work also involves Ti 2 NT x MXene for ORR applications, reporting that Ti 2 NT x vastly outperforms Ti 3 C 2 T x in terms of stability and activity and benchmark Pt/C in terms of stability. 20 Ti 2 NT x MXene was also shown to have faster reaction kinetics compared to both the counterpart Ti 3 C 2 T x MXene and benchmark Pt/C. A work by Yoo and Djire reports the Ti 2 NT x MXene to have a high HER electrocatalytic activity under 0.5 M KOH, achieved through modifications of the overall synthesis process.…”

“…Furthermore, previous research suggests that nitride-based MXenes exhibit better pseudocapacitive performance than their carbide counterparts. Out of the currently available nitride MXenes, Ti 2 NT x has been widely investigated experimentally. − In particular, Ti 2 NT x was predicted to have high capacitance and wide voltage windows, suggesting its potential for future energy storage applications. Yogendra et al analyzed a defective and strained Ti 2 NT x structure with DFT calculations, suggesting that Ti 2 NO 2 exhibits exotic electronic structures and magnetic states in pristine, strained, and defective structures, which shows its potentially promising application for semiconductors through surface modification.…”

“…For example, an experimental work by Johnson et al reports the Ti 2 NT x MXene to have a favorable nitrogen reduction reaction (NRR) selectivity via the Mars–van Krevelen (MvK) mechanism and especially outperforming the Ti 3 C 2 T x carbide counterpart, with a Faradaic efficiency of 19.85% compared to that of 0.58% . Another related experimental work also involves Ti 2 NT x MXene for ORR applications, reporting that Ti 2 NT x vastly outperforms Ti 3 C 2 T x in terms of stability and activity and benchmark Pt/C in terms of stability . Ti 2 NT x MXene was also shown to have faster reaction kinetics compared to both the counterpart Ti 3 C 2 T x MXene and benchmark Pt/C.…”