PhD defence

Perovskite-based Photoelectrochemical Investigations for Artificial Photosynthesis

• T. Guo

Date

Tuesday 21 January 2025

Time

10:00 - 11:00 hour

Address

Academy Building
Rapenburg 73
2311 GJ Leiden

Supervisor(s)

• Prof.dr. H. de Groot
• dr. W. T. Fu

Summary

Inspired by natural photosynthesis, perovskite-based photoelectrochemical (PEC) systems are being developed for artificial photosynthesis, aiming to enhance solar-to-hydrogen conversion for green energy. This program focuses on the Ba₂Bi₂O₆ (BBO) double perovskite, a material with tunable chemical and structural flexibility, engineered to realize efficient solar energy conversion. Through controlled doping, film thickness optimization, and concentration adjustments, a series of BBO-based photoelectrodes with tailored band gaps, crystal structures, and varying PEC performances were systematically investigated. Doping with pentavalent Nb5+ and Ta5+ ions induced a rhombohedral crystal structure and increased band gaps (1.5-2.3 eV), enhancing electrochemical stability but yielding modest photocurrents. In contrast, doping with La3+, Ce4+, Pr3+/Pr4+, and Pb4+ ions led to monoclinic structures, while Y3+ doping resulted in a mix of monoclinic and cubic phases. The doped B1–O–B2 network remained highly ordered in La3+ and Y3+ systems, became partially ordered with Pr3+/Pr4+, and disordered with Ce4+ and Pb4+. Optical band gaps increased to 1.57 eV and 1.73 eV in La3+ and Pr3+/Pr4+ doped systems, respectively, compared to the parent BBO material. Notably, the La3+-doped system demonstrated improved electrochemical stability and superior photocurrents, offering promising insights for future optimization of PEC materials for sustainable hydrogen production.

PhD dissertations

Approximately one week after the defence, PhD dissertations by Leiden PhD students are available digitally through the Leiden Repository, that offers free access to these PhD dissertations. Please note that in some cases a dissertation may be under embargo temporarily and access to its full-text version will only be granted later.

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