TEMPERATURE DEPENDENCE OF PHOTOCATALYTIC DEGRADATION OF RHODAMINE B IN THE PRESENCE OF G-C3N4 STRUCTURES
Rubrics: 1. CHEMISTRY
Authors:
1.
KNITU
3.
Kazan National Research Technological University
Kazanskiy Fiziko-Tehnicheskiy Institut im. E.K. Zavoyskogo FIC KazNC RAN
Russian Federation
Kazanskiy Fiziko-Tehnicheskiy Institut im. E.K. Zavoyskogo FIC KazNC RAN
Russian Federation
Type:
Article
Pages:
from 27
to 30
Status:
Published
Received:
22.12.2025
Accepted:
23.12.2025
Published:
23.12.2025
Language:
Russian
Keywords:
CARBON NITRIDE, PHOTOCATALYSIS, RHODAMINE B, VISIBLE LIGHT, EFFECT OF TEMPERATURE
Abstract (English):
The problem of water purification from persistent organic pollutants requires the development of effective and environmentally friendly methods. One of the most promising is photocatalytic oxidation under the action of visible light, which allows using solar energy for pollutant mineralization. A promising photocatalyst for this process is graphitic carbon nitride (g-C3N4), which is capable of being activated by visible light, is easy to synthesize, has low cost and high stability. In this paper, a systematic study of the effect of temperature (in the range of 15-45 °C) on the efficiency of photocatalytic decomposition of a model pollutant - Rhodamine B in the presence of g-C3N4 catalyst synthesized by thermal condensation of melamine is carried out. The formation of the structure of the catalyst was confirmed by IR Fourier and UV-visible spectroscopy methods and its optical properties were studied. It was found that an increase in the temperature of the reaction medium leads to a significant increase in the rate of photocatalytic degradation of the dye. The reaction rate constant increased threefold - from 0.0288 min⁻¹ at 15°C to 0.0886 min⁻¹ at 45°C. It was shown that the observed effect is due to the activation of temperature-dependent stages of the process: an increase in the migration rate and a decrease in the recombination of photogenerated charge carriers, acceleration of surface reactions and effective desorption of products. It was found that in the studied range, the positive kinetic effect of increasing the temperature exceeds the possible decrease in the equilibrium adsorption of the pollutant. The results of the work demonstrate that even moderate heating is an effective tool for overcoming kinetic limitations and significantly increasing the productivity of photocatalytic systems based on g-C3N4, which is important for the practical implementation of energy-efficient and cost-effective solar driven water purification systems.
The problem of water purification from persistent organic pollutants requires the development of effective and environmentally friendly methods. One of the most promising is photocatalytic oxidation under the action of visible light, which allows using solar energy for pollutant mineralization. A promising photocatalyst for this process is graphitic carbon nitride (g-C3N4), which is capable of being activated by visible light, is easy to synthesize, has low cost and high stability. In this paper, a systematic study of the effect of temperature (in the range of 15-45 °C) on the efficiency of photocatalytic decomposition of a model pollutant - Rhodamine B in the presence of g-C3N4 catalyst synthesized by thermal condensation of melamine is carried out. The formation of the structure of the catalyst was confirmed by IR Fourier and UV-visible spectroscopy methods and its optical properties were studied. It was found that an increase in the temperature of the reaction medium leads to a significant increase in the rate of photocatalytic degradation of the dye. The reaction rate constant increased threefold - from 0.0288 min⁻¹ at 15°C to 0.0886 min⁻¹ at 45°C. It was shown that the observed effect is due to the activation of temperature-dependent stages of the process: an increase in the migration rate and a decrease in the recombination of photogenerated charge carriers, acceleration of surface reactions and effective desorption of products. It was found that in the studied range, the positive kinetic effect of increasing the temperature exceeds the possible decrease in the equilibrium adsorption of the pollutant. The results of the work demonstrate that even moderate heating is an effective tool for overcoming kinetic limitations and significantly increasing the productivity of photocatalytic systems based on g-C3N4, which is important for the practical implementation of energy-efficient and cost-effective solar driven water purification systems.
Keywords:
CARBON NITRIDE, PHOTOCATALYSIS, RHODAMINE B, VISIBLE LIGHT, EFFECT OF TEMPERATURE
CARBON NITRIDE, PHOTOCATALYSIS, RHODAMINE B, VISIBLE LIGHT, EFFECT OF TEMPERATURE
