These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
Pedireddy et al_Manuscript_chemrxiv_Nov2020.pdf (2 MB)

Unlocking the Potential of Single Atoms Loaded Geobacter Hybrid Catalyst as Bifunctional Electrocatalyst for Water Splitting

revised on 06.11.2020, 14:56 and posted on 09.11.2020, 06:42 by Srikanth Pedireddy, Mahesh Kumar Ravva, Chandrani Nayak, Dalaver Anjum, Shambhu Nath Jha, Krishna P. Katuri, Pascal Elias Saikaly
Single-atom metal (SA-M) catalysts with high dispersion of active metal sites allow maximum atomic utilization. However, conventional synthesis of SA-M catalysts involves high-temperature treatments, leading to a low yield with random distribution of atoms. Herein, a facile method to synthesize SA-M catalysts (M = Fe, Ir, Pt, Ru, Cu, or Pd) in a single step at ambient temperature, using the extracellular electron transfer capability of Geobacter sulfurreducens (GS), is presented. Interestingly, the SA-M is coordinated to three nitrogen (N) atoms adopting an MN3 on the surface of GS. Dry samples of SA-Ir@GS without further heat treatments show exceptionally high activity for OER when compared to benchmark IrO2 catalyst and comparable HER activity to commercial 10 wt.% Pt/C. The SA-Ir@GS electrocatalyst exhibits the best water‐splitting performance compared to other SA-M@GS, showing a low applied potential of 1.65 V to achieve 10 mA cm−2 in 1.0 M KOH solution with cycling over 5 h. The density functional calculations reveal that the large adsorption energy of H2O and moderate adsorption energies of reactants and reaction intermediates for SA-Ir@GS favorably improve its activity. This nature-based facile synthesis method of SA-M at room temperature provides a versatile platform for the preparation of other transition metal SA-M catalysts for various energy-related applications by merely altering the metal precursors.


This work was supported by Competitive Research Grant (URF/ 1/2985-01-01) from KAUST to PES.


Email Address of Submitting Author


King Abdullah University of Science and Technology


Saudi Arabia

ORCID For Submitting Author


Declaration of Conflict of Interest

The authors declare no conflict of interest.