6–10 Jul 2026
University of the Western Cape
Africa/Johannesburg timezone
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Concentration-dependent effects of caffeine on perovskite catalysts for electrocatalytic and photoelectrocatalytic hydrogen evolution reaction

7 Jul 2026, 17:20
1h 20m
Great Hall (University of the Western Cape)

Great Hall

University of the Western Cape

Poster Presentation Track A - Physics of Condensed Matter and Materials Poster Session 1

Speaker

Dieketseng Glara Tsotetsi (Department of Physics, University of South Africa, Johannesburg, 1710, South Africa.)

Description

In this study, optimizing caffeine concentrations (2%, 4%, 6%, and 8%) in MAPbI3 using a graphite electrode under acidic conditions, analysing both electrocatalytic (EC) and photoelectrocatalytic (PEC) processes was investigated. The catalyst made from Graphite and MAPbI3 with 2% caffeine shows superior performance compared to the other catalysts, particularly in the dynamic electrocatalytic process. Notably, the Graphite + MAPbI3@Caffeine 2% catalyst exhibits a significantly reduced charge transfer resistance of 9.27 ꭥ, outperforming the other catalysts we examined. Our results also indicate that the Graphite + MAPbI3@Caffeine 4% loading demonstrates exceptional stability, surpassing the stability of other catalysts. Remarkably, the double-layer capacitance (Cdl) value for the Graphite + MAPbI3@Caffeine 2% electrode is 0.00281 F/cm², which indicates a significant enhancement under PEC conditions compared to EC settings, with an effective catalyst surface area (ECSA) of 150 cm². Additionally, the turnover frequency (TOF) for the Graphite + MAPbI3@Caffeine 2% catalyst was calculated to be an impressive 348.29 s⁻¹, exceeding the performance of other electrodes within the EC process.

Author

Dieketseng Glara Tsotetsi (Department of Physics, University of South Africa, Johannesburg, 1710, South Africa.)

Co-authors

Prof. Bakang Mothudi (Centre for Materials Science, University of South Africa, Johannesburg, 1710, South Africa.) Prof. Mokhotjwa Dhlamini (Department of Physics, University of South Africa, Johannesburg, 1710, South Africa) Dr Olayemi Fakayode (Centre for Materials Science, University of South Africa, Johannesburg, 1710, South Africa.) Dr Tumelo Seadira (Department of Chemical and Material Engineering, University of South Africa, Johannesburg, 1710, South Africa.)

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