Status : Verified
| Personal Name | Gonzaga, Ian Lorenzo E. |
|---|---|
| Resource Title | Bilayered CuBi2O4/CuO Nanocomposite Films for the Photoelectrochemical Reduction of CO2 |
| Date Issued | September 2022 |
| Abstract | Solar energy is free, clean, and virtually limitless; however, its conversion into a storable form presents technological challenges. Compared to batteries or other mechanical systems, fuels are more energy-dense, directly usable, and compatible with the current energy infrastructure. One scheme to produce “solar fuels” is the photoelectrochemical (PEC) reduction of CO2 to one- or two-carbon compounds, where a semiconductor configured as an electrode performs both the light absorption and electrochemical functionalities. A potential material for this application is the p-type copper bismuth oxide (CuBi2O4) with a band gap capable of visible light absorption and a conduction band edge position suitable for CO2 reduction. In this study, CuBi2O4 photocathodes were prepared via an electrodeposition-spray deposition-annealing route. By varying the number of spray cycles, films with varying Cu/Bi ratios (0.25, 0.51, 0.68, 0.94, 2.04) were synthesized. Where the ratio exceeded the stoichiometric value of 0.5, a bilayered film composed of a nanoparticulate copper (II) oxide (CuO) phase on top of CuBi2O4 was present, forming a heterojunction between the two oxide layers. With increasing Cu/Bi ratio, the light absorption range of the films broadened due to the CuO phase. Analysis of the photocurrent-potential behavior of the films under visible-light illumination showed a 4–7-fold increase in the photocurrent from an inert electrolyte to a CO2-saturated electrolyte, confirming activity for CO2 reduction of the CuBi2O4/CuO films. The transient photocurrent response of the films showed a 70-80% decrease in the photocurrent after only 15 mins of testing. However, when tested in an electrolyte with an electron scavenger, the percent decrease was lowered to <10%, indicating that the instability of the films resulted from poor interfacial kinetics. While the CuBi2O4/CuO films can accomplish CO2 reduction, further strategies to improve their efficiency and stability are needed |
| Degree Course | Master of Science in Materials Science and Engineering |
| Language | English |
| Keyword | artificial photosynthesis; photoelectrochemical CO2 reduction; copper oxide photocathodes |
| Material Type | Thesis/Dissertation |
Preliminary Pages
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Category : F - Regular work, i.e., it has no patentable invention or creation, the author does not wish for personal publication, there is no confidential information.
Access Permission : Open Access