Effect of Nitrogen Species in Graphite Carbon Nitride on Hydrogen Peroxide Production

Abstract

Electrochemical oxygen reduction for producing clean hydrogen peroxide (H2O2) is a promising alternative approach to the industrial anthraquinone method. At present, the most pressing challenge is the development of oxygen reduction electrocatalysts with sufficient activity, stability, and 2e− pathway selectivity. Here, the electrocatalytic properties of a series of graphitic carbon nitride (g‐C3N4) catalysts with different concentrations of nitrogen species (CNC and N(C)3) are explored for H2O2 production. Electrochemical studies show that the selectivity of g‐C3N4 for hydrogen peroxide generation in alkaline electrolytes reaches ≈90%. To explain the observed results, the structure, composition, and physical and chemical properties of g‐C3N4 catalysts synthesized from different precursors are compared with their electrocatalytic performance. This research contributes to the discovery and design of a high‐performance nitrogen‐doped carbon catalysts for the production of hydrogen peroxide.

Defect Engineering of Porous g-C3N4 to Add Multifunctional Groups for Enhanced Production of H2O2 via Piezo-Photocatalysis

“…Otherwise, the pyridinic N would be more favorable to the 4e – ORR pathway with evidence from Zheng et al’s work on fabricating pyridinic N-rich carbon spheres for the efficient reduction of oxygen . Understandably, the pyridinic N could induce the positive charge on the adjacent C, helping the transportation of electrons from the bonding and antibonding orbitals of oxygen to weaken the O–O bonds. − Accordingly, the calculated ratios between graphitic and pyridinic N species from the XPS-deconvoluted areas of these peaks were at a value of 0.54, 0.80, 0.75, and 0.76 for CN, BCN, CCN, and MCN, respectively. Thereby, the proportion of N–(C 3 ) and CN–C in this study was lower than 1, indicating that the 4e – ORR or indirect 2e – ORR pathway could mainly dominate the catalytic mechanism.…”

Revisiting the roles of dopants in g-C3N4nanostructures for piezo-photocatalytic production of H2O2: a case study of selenium and sulfur

“…4b with four distinct peaks, comprising p-p* electron transitions in the networks at around 404.5 eV for all samples, graphitic N, pyrrolic N, and pyridinic N. 37,41 Notably, the peak was at 399.7, 400.3, 400.2, 399.8, and 400.1 eV for GCN, SCN, p-SCN, p-SeCN, and SeCN, respectively, indicating the presence of graphitic N. In contrast, the peaks centered at 398.6, 398.6, 398.7, 398.6, and 398.6 eV for these samples were associated with pyridinic N in the systems. The remaining peak located at 401.1, 401.2, 401.4, 401, and 401.3 eV belonging individually to GCN, SCN, p-SCN, p-SeCN, and SeCN was ascribed to pyrrolic N. It has been stated that pyridinic N would favor the indirect two-electron oxygen reduction reaction (2e − ORR), in contrast with a direct pathway of graphitic N. 42,43 Thus, estimating the dominative reaction mechanism in the research is feasible via computing the ratio between these features. The calculated area ratios between graphitic N and pyridinic N are presented in Table S4, † which are 0.199, 0.199, 0.346, 0.341, and 0.265 for GCN, SCN, p-SCN, p-SeCN, and SeCN.…”

High-efficiency oxygen reduction by late transition metal oxides to produce H2O2

“…14 To address this issue, it is crucial to develop stable and efficient catalysts that protect O-O bonds and exhibit appropriate HOO* adsorption effects during the ORR process. [15][16][17] Noble metals and their alloys, such as Pt-Ag, Pt-Hg, and Pd-Au, have proven to be effective electrocatalysts. 18,19 However, their limited availability and high cost hinder them from being widely used.…”