1Matériaux & Ingénierie Mécanique, Université de Reims Champagne-Ardenne, France
2Laboratoire de Physique de la Matière Condensée, Université de Picardie-Jules Verne, France
*Corresponding author: Aomar Hadjadj, Matériaux & Ingénierie Mécanique, Université de Reims Champagne-Ardenne, France
Submission: September 21, 2021; Published: September 27, 2021
ISSN : 2578-0255Volume7 Issue3
Forecasts for the global textile dyes market would indicate a growth from some US $7 billion in 2019 to more than US $13 billion in 2027, despite stringent environmental regulations [1]. This high consumption of dyes, added to other human activities, will produce large quantities of waste that will end up, most often, in wastewater. Already now, 100 tons of dyes are released annually in effluents by industry [2]. The search for efficient and inexpensive methods for the treatment of these polluted waters is more than topical. Photocatalytic degradation is an effective method to treat this contaminated water and thus reduce environmental pollution. In addition, associating the solar resource in heterogeneous photocatalysis is an additional factor to boost the search for innovative photocatalysts capable of eliminating dyes, pesticides, fertilizers, bacteria, etc., during the treatment of contaminated wastewater. Currently, the most promising semiconductor in this field is ZnO. This wide band gap semiconductor is known for its chemical stability, its non-toxicity, its interesting optoelectronic properties, and the relative ease to deposit it in thin films. Figure 1a shows the growth in the number of publications devoted to the use of ZnO in dye degradation. These publications mainly address the following dyes: Methylene Blue (39%), Methyl Orange (31%) and Rhodamine B (23%). Although Indigo Carmine is the most used for dyeing fibers (like jeans) and despite its harmful effects (toxic and non-biodegradable, its molecule is very difficult to degrade), the share of publications devoted to this dye does not exceed 6%.