Version 1
: Received: 18 August 2019 / Approved: 19 August 2019 / Online: 19 August 2019 (04:14:30 CEST)
How to cite:
Kushagra, A.; Pandey, A. Generation of Optical Absorption Band in Colloidal Coffee at Extremely Alkaline pH. Preprints2019, 2019080192. https://doi.org/10.20944/preprints201908.0192.v1
Kushagra, A.; Pandey, A. Generation of Optical Absorption Band in Colloidal Coffee at Extremely Alkaline pH. Preprints 2019, 2019080192. https://doi.org/10.20944/preprints201908.0192.v1
Kushagra, A.; Pandey, A. Generation of Optical Absorption Band in Colloidal Coffee at Extremely Alkaline pH. Preprints2019, 2019080192. https://doi.org/10.20944/preprints201908.0192.v1
APA Style
Kushagra, A., & Pandey, A. (2019). Generation of Optical Absorption Band in Colloidal Coffee at Extremely Alkaline pH. Preprints. https://doi.org/10.20944/preprints201908.0192.v1
Chicago/Turabian Style
Kushagra, A. and Akshaya Pandey. 2019 "Generation of Optical Absorption Band in Colloidal Coffee at Extremely Alkaline pH" Preprints. https://doi.org/10.20944/preprints201908.0192.v1
Abstract
Coffee and caffeine have been used as solar absorbers and also to increase the thermal stability and efficiency of perovskite solar cells. In this work, we report the sensing of extremely alkaline pH by colloidal coffee solution aided by generation of an optical absorption band in the near-UV region. This generation of absorption band could be explained by the orientation induced dipole-dipole interactions arising from differing caffeine-solvent interactions with varying pH. Such a generation leads to the lowering of direct as well as indirect bandgaps from 4 eV-->2.8 eV& 3.4 eV-->2.5 eV, respectively. We also estimate the changes in optical energy storage efficiency, inferring it to be highest for pH 11 having the highest intensity of the generated absorption band (λ_abs≈360 nm). With these observations and further deductions, the work reported in this paper would be of immense interest to the researchers working in the field of development of chemical pH sensors and also in the development of novel UV absorbers.
Chemistry and Materials Science, Applied Chemistry
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.