Solid state synthesis of silver doped graphitic carbon nitride and its efficacy in removing textile dyes

The work reports the synthesis of silver doped graphitic carbon nitride (GCN) using urea as precursor. Both the pure and doped samples were characterized by X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM), Energy-dispersive X-ray spectroscopy (EDX) and Fourier transformed infrared (FTIR) spectroscopy analysis.

XRD confirmed the proper phase formation of the samples with preferential growth along (002) direction whereas FESEM shows the growth of chip-like morphologies with high yield, EDX analysed the stoichiometric ratio of sample and FTIR revealed the different vibrational energy level present.

The efficacies of the samples in degrading Bengal Rose under UV light irradiation was studied. The results demonstrated that the doped samples exhibited excellent dye removal performance, achieving an efficiency of more than 85 % within just 40 min. Not only that, here the electrical energy per order as well as degradation turnover of both samples were calculated and shown that the doped sample has much higher promises compared to pure GCN. Especially, degradation turnover came out to be over 95 % for the doped sample with an exposure time of just 10 min.

When reaction kinetics was studied it is seen that the reaction mainly followed 1st order kinetics with regression coefficient almost unity. Here also doped sample showed faster kinetics with reaction constant value 0.050/minute.

It has been concluded that dopant create intermediate energy states where charge carrier can rest prolonging electron hole pair recombination which in turn facilitate the interaction with dyes and thus enhancing its removal performance.