The knowledge of how the different types of nitrogen centers affect the electrochemical and optical prop- erties of Nitrogen-doped carbon quantum dots (N-CDs) is of paramount importance in the design and synthesis of these nanostructures. In fact, from the knowledge of the redox centers of N-CDs it is possi- ble tune their energetic levels in order to realize the suitable matches for the design of opto-electronic, photovoltaic or catalytic devices. Herein we present a study of the electrochemical and the optical re- sponses of N-CDs, obtained by hydrothermal method from citric acid and urea. The main issue is to investigate the role played by the specific nitrogen centers in their redox processes. From the voltam- metric responses we showed that the observed oxidation processes of N-CDs involve their graphitic and pyrrolic N-atoms, respectively, while the reduction process regards their protonated pyridinic N-atoms. Then, from spectro-electrochemical determinations, we explained that the oxidation of the graphitic N- atoms is a two electron process that gives an N -oxide form through the reaction with a molecule of water and the loss of two protons. Finally we discussed the observed pH-dependence of both the optical and the electrochemical responses of our N-CDs to explain the role played by their pyridinic N-atoms.<\/p>\n","protected":false},"excerpt":{"rendered":"
Vercelli B.; Donnini R.; Ghezzi F.; Sansonetti A.; Giovanella U.; La Ferla B.<\/p>\n","protected":false},"featured_media":1294,"comment_status":"closed","ping_status":"open","template":"","meta":[],"product_cat":[574],"product_tag":[2939,2940,2941,2942,2943],"class_list":["post-7642","product","type-product","status-publish","has-post-thumbnail","hentry","product_cat-journal-articles","product_tag-nitrogen-doped-carbon-quantum-dots","product_tag-hydrothermal-method","product_tag-electrochemistry","product_tag-redox-centers","product_tag-optical-properties","prodpage-style2"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.istp.cnr.it\/it\/wp-json\/wp\/v2\/product\/7642","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.istp.cnr.it\/it\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/www.istp.cnr.it\/it\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/www.istp.cnr.it\/it\/wp-json\/wp\/v2\/comments?post=7642"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.istp.cnr.it\/it\/wp-json\/wp\/v2\/media\/1294"}],"wp:attachment":[{"href":"https:\/\/www.istp.cnr.it\/it\/wp-json\/wp\/v2\/media?parent=7642"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.istp.cnr.it\/it\/wp-json\/wp\/v2\/product_cat?post=7642"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.istp.cnr.it\/it\/wp-json\/wp\/v2\/product_tag?post=7642"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}