Carbon Nanotubes Grown on CuO Nanoparticle-Decorated Porous Carbon Microparticles for Water Oxidation

Abstract

Efficient water splitting is limited by the sluggish oxygen evolution reaction (OER) to a large extent, which inhibits the development of sustainable energy and has attracted widespread attention. In this work, a type of microsized Cu-based metal−organic framework (MOF) of Cu-BTB has been successfully synthesized by a rapid reaction within half an hour. During the subsequent pyrolysis, a large number of N-containing carbon nanotubes (NCNTs) are grown on the entire surface of hierarchically porous MOF-derived nanosized carbons through the introduction of ethylene and ammonia, denoted as NCNT/Cu/C. After oxidation, NCNT-supported nanosized copper oxide embedded in a carbon matrix (NCNT/CuO/C) is finally obtained to show the preserved morphology and high graphitization degree. The high specific surface area and conductivity of NCNTs for NCNT/CuO/C further enable the electrolyte to make better contact with the active materials during the OER. Finally, the optimal nanosized NCNT/CuO/C exhibits a high degree of improvement in OER performance, in which it attains an overpotential of only 369 mV at 10 mA cm −2 , and its Tafel slope is calculated to be 87.4 mV dec −1 , indicating fast reaction kinetics. The demonstrated work proves that the method of doping NCNTs with nanosized copper oxides can effectively enhance the efficacy of water oxidation, which can be further used in future energy applications.

Characterization of NOx Release during Combustion Synthesis and Cyclic Reaction Performance of Cu-Based Oxygen Carriers Prepared with Citric Acid

“…With the increase of R , the characteristic peak of Cu + showed a leftward shift, the electron binding energy increased, and more Cu 2+ was formed. These represented a fuller oxidation of the OC …”

Prepatterned Cyanuric Acid Template for Reaching the Theoretical Upper Limit of Nitrogen-Doped Graphene for Nonradical Oxidation

“…27 The N-doping level of TUNPG could reach 10.10 atom % (Figure S5), higher than other reports (Table S1), even close to the theoretical upper limit of 12.5 atom % at 1000 °C. 28 In order to demonstrate that the prepatterned cyanuric acid in melamine-cyanurate enabled the formation of TUNPG, the thermal behaviors of melamine-cyanurate (with cyanuric acid) and melamine (without cyanuric acid) with the existence of 2benzimidazolethiol were compared. Different from the pyrolysis of melamine, a sharp exothermic peak was observed during the pyrolysis of melamine-cyanurate at 440 °C (Figure 2a).…”

Graphitic N-Rich Graphene for Nonradical Peroxymonosulfate Activation

“…14 It was reported that graphitic N in nitrogen-doped graphene could induce nonradical PMS activation. 15 As a result, hydrothermal and calcination methods have been developed to prepare nitrogen-doped graphene with high graphitic N content. 16 However, these methods involve the preparation of a graphene oxide precursor and its reaction with different nitrogen sources, suffering from high complexity, low productivity, and low doping content.…”