‘Total electrode’ and ‘intrinsic’ activity parameters in water electrolysis: a comprehensive investigation

Abstract

Various electrochemical activity markers were distinguished based on their intrinsic and extrinsic behaviours. A detailed experiment portrays the importance of properly reporting the activity in terms of intrinsic electrochemical parameters.

Binary Ni–Cu nanocomposite-modified MXene-adorned 3D-nickel foam for effective overall water splitting and supercapacitor applications

“…The turnover frequency (TOF), which measures the quantity of product generated or reactant consumed per unit time for a given amount of catalyst, is an intrinsic activity marker that may be used to estimate how effective a catalyst is for the reaction of interest. Typically, the following equation is utilized in water-splitting applications to calculate the TOF: 54 TOF = j × N A / n × F × τ where, j is the current density obtained as a function of the overpotential, N A is Avogadro's number, n is number of electrons transferred, which is 2 for the hydrogen evolution reaction and 4 for the oxygen evolution reaction, F is Faraday's constant, and τ represents the number of active sites. According to the surface charge information, the τ value of the catalyst can be calculated as follows: τ : amount of surface accumulated charge/1.602 × 10 −19 …”

Three-Dimensional Network of Highly Uniform Cobalt Oxide Microspheres/MXene Composite as a High-Performance Electrocatalyst in Hydrogen Evolution Reaction

“…where m, M, I, t, N, and F represent the amount of produced H 2 , molecular weight, current density at a particular overpotential, time (h), number of electrons transferred, and Faraday's constant, respectively. 60 Chronopotentiometry at 10 mA cm −2 for 24 h showed that Co 3 O 4 /MXene is stable in alkaline circumstances (Figure 5), with polarization curves changing by just 19 mV. Furthermore, the characterizations, including TEM image and EIS Nyquist plots of Co 3 O 4 /MXene after the stability test (Supporting Information Figure S7), were examined.…”

“…Most of the HER electrocatalysts that have been reported have a Coulombic efficiency of 100% due to the absence of any usual competing reactions. , Consequently, the quantity of hydrogen is theoretically determined by applying Faraday’s second law of electrolysis . The mathematical expression of Faraday’s second law is as follows m = M × I × t N × F where m , M , I , t , N , and F represent the amount of produced H 2 , molecular weight, current density at a particular overpotential, time (h), number of electrons transferred, and Faraday’s constant, respectively …”

Engineering 2D nickel boride/borate amorphous/amorphous heterostructures for electrocatalytic water splitting and magnetism

“…5,13,14 Transition metal-based materials are the most promising to be used for structuring heterostructures since they possess superior physicochemical properties as needed in energy applications such as water electrolysis. [15][16][17][18][19][20] To date, crystalline/crystalline heterostructures are studied the most due to their well-dened heterointerfaces, their plethora of synthesis methods, and ease of structural characterisation. 21 On the other hand, amorphous/crystalline heterostructures are starting to become the focus of recent studies, as amorphous nanomaterials usually possess remarkable superior properties compared to their crystalline counterparts.…”

“…5,13,14 Transition metal-based materials are the most promising to be used for structuring heterostructures since they possess superior physicochemical properties as needed in energy applications such as water electrolysis. 15–20…”