Protonated C3N4 Nanosheets for Enhanced Energy Storage in Symmetric Supercapacitors through Hydrochloric Acid Treatment oleh Mahalakshmi Subbiah, Annalakshmi Mariappan, Anandhakumar Sundaramurthy, Sabarinathan Venkatachalam, Rajasekaran Thanjavur Renganathan, Nishakavya Saravanan, Sudhagar Pitchaimuthu, Nagarajan Srinivasan