Influence of non-metal dopants (O, S, N) and dimension of carbon nano materials on the fluorescence and photocatalytic degradation of organic pollutants

Abstract

The usage of sanitizers and disinfectants results in the dumping of toxic organic residues in water. There is a global need for effective agents which can adsorb and degrade hazardous chemicals effectively and convert into much safer constituents. In this study, the influence of non-metal dopants (O, S, N) and dimensionality on the catalytic ability of carbon nanomaterials (CNs) such as 0-D (Nitrogen-doped Carbon quantum dots (N-CQDs) synthesized from the seed kernel of Caesalpinia bonducella) and 2-D (Graphene oxide (GO), Sulphur doped graphene oxide (S-GO), Nitrogen-doped graphene oxide (N-GO) synthesized from glucose) have been compared and correlated. The microstructure, surface morphology, elemental composition, fluorescence emission and catalytic ability of the 0-D and 2-D materials are determined and compared. The defect density and the sub defect band gap states influenced by different electronegative non-metal dopants and the dimensions are discussed. The Micro strain increases with increases in dimension. The percentage of Nitrogen as dopant in N-GO is relatively less compared with N-CQDs which led to less fluorescence intensity observed in N-GO. On comparison of the results, it is evident that greater electro negativity of the dopants and reduction in dimension will increase the photo catalytic activity. Also, in comparison with 2-D structures, the large surface area and greater quantum confinement of 0-D structure enhance the degradation of organic pollutants. This observation is well correlated with PL emission intensities of the compared CNs. The results provide a better correlation between dimensionality and functionality of CNs and their impact on catalytic (adsorption and photo) applications in experimentally possible ways.