Ni-doping can substantially increase the p[erformance of electrochemical water splitting in the case of WC or MoC lattice. In situ XAFS shows the charge transfer between Ni and W/Mo which is the origin of better HER/OER performance in the wide pH range of electrolytes.

1. Mechanistic Insights into the Promotional Effect of Ni Substitution in
Non-noble Metal Carbides for Highly Enhanced Water Splitting
Debabrata Bagchi
(Oral Presentation No. T10A38)
Supervisor: Prof. Sebastian C. Peter
JNCASR, Bangalore
3rd Indian Materials Conclave and 32nd Annual General Meeting of MRSI
(23/12/2021)

2. Global Outlook : Hydrogen as an alternative Energy
2
Energy consumption TWh/y
> 85%–Fossil Fuels
Hydrocarbons: Finite sources
– Non-renewable
7.914 Billion,
December 2021
World Population by region
climate.nasa.gov https://www.co2.earth
Statistical Review of World Energy, Workbook, London, 2016

3. Han, W. et al., Frontiers in Chemistry 2020, 8, 1025
Electrochemical Water Splitting: Catalyst for HER & OER
3
Hydrogen Evolution Oxygen Evolution
Seh, Z. W. et al., Science 2017, 355, eaad4998
Platinum (Pt) is known as the
state-of-art catalyst for HER.
IrO2 and RuO2 is known as the
state-of-art catalyst for OER.
Low cost
alternative catalyst
?

4. Polyoxometalate
(H3PW12O40/ H3PMo12O40)
Melamine
4
Catalyst Design Strategy: Ni-WC/MoC@NGC
Ball Milled
Mole Ratio (W:Ni:Mel)
5:0:20
5:1:20
5:2:20
5:3:20
900 °C@5h
Ni
N
Ni-Mo/WC@NGC

5. Characterizations
XPS study
5
Powder XRD Raman Spectra
Ni-doping from XRD shift Oxidation state of W/Mo & Ni from XPS
Defect in C matrix & N-
doping

6. Microscopic Analysis
6
Ni-MoC@NGC
Ni-WC@NGC

7. Hydrogen Evolution Reaction (HER) in 0.5M H2SO4
Hydrogen Evolution Reaction (HER) in 0.5M H2SO4
Hydrogen Evolution Reaction (HER) in 0.5 M H2SO4
7
Activity Stability Tafel Slope
Impedance Chronoamperometric Stability

8. Hydrogen Evolution Reaction (HER) in 0.5M H2SO4
Hydrogen Evolution Reaction (HER) in 0.5M H2SO4
HER in 0.5 M KOH
8
Activity Stability Tafel Slope
Impedance Chronoamperometric Stability
Ni-doping enhancing
the activity of carbide

9. Hydrogen Evolution Reaction (HER) in 0.5M H2SO4
Hydrogen Evolution Reaction (HER) in 0.5M H2SO4
Oxygen Evolution Reaction (OER) in 0.5 M KOH
9
Activity Stability
Tafel Slope
Chronoamperometric Stability
IrO2

10. In-situ X-ray Absorption Spectroscopic Analysis
Detector X-ray source
ECell set-up
Experiment was performed at PETRA III, beamline P64, of DESY, Germany. 10

11. WC@NGC
10206 10209 10212
1.8
1.9
2.0
2.1
0.225
1st Role of Ni: HER in Acid
11
10208 10210 10212 10214
2.4
2.6
2.8 0.15
Ni-WC@NGC
Ni-Edge
In-situ XAS Ex-situ XAS

12. 2nd Role of Ni: OER in Base
3rd Role of Ni: Dissolution and Site Vacancies
12
Computational Understanding
Ni-Edge
Theoretical calculation was performed in collaboration with Prof. Waghmare, JNCASR.

13. Hydrogen Evolution Reaction (HER) in 0.5M H2SO4
Hydrogen Evolution Reaction (HER) in 0.5M H2SO4
Overall Water Splitting in 0.5M KOH
13
Correlation of overpotentials
Stability
Production of
H2 & O2

14. 14
Summary
0.5M KOH
Cathode
Anode H2
O2
Activity Stability Mechanism Role of Ni
D. Bagchi, S. Roy, L. Dheer, S. C. Sarma, V. Rajaji, C. Narayana, U. V.
Waghmare, S. C. Peter, Appl. Catal. B, 2021, 298, 20560.
I. F. -19.503

15.  My supervisor, Prof. Sebastian C. Peter for his constant support and encouragement
 All my present and past lab members
Thank you…
Acknowledgement