Synergistic Effects in N,O‐Comodified Carbon Nanotubes Boost Highly Selective Electrochemical Oxygen Reduction to H₂O₂

Abstract

Electrochemical 2‐electron oxygen reduction reaction (ORR) is a promising route for renewable and on‐site H2O2 production. Oxygen‐rich carbon nanotubes have been demonstrated their high selectivity (≈80%), yet tailoring the composition and structure of carbon nanotubes to further enhance the selectivity and widen working voltage range remains a challenge. Herein, combining formamide condensation coating and mild temperature calcination, a nitrogen and oxygen comodified carbon nanotubes (N,O‐CNTs) electrocatalyst is synthesized, which shows excellent selective (>95%) H2O2 selectivity in a wide voltage range (from 0 to 0.65 V versus reversible hydrogen electrode). It is significantly superior to the corresponding selectivity values of CNTs (≈50% in 0–0.65 V vs RHE) and O‐CNTs (≈80% in 0.3–0.65 V vs RHE). Density functional theory calculations revealed that the C neighbouring to N is the active site. Introducing O‐related species can strengthen the adsorption of intermediates *OOH, while N‐doping can weaken the adsorption of in situ generated *O and optimize the *OOH adsorption energy, thus improving the 2‐electron pathway. With optimized N,O‐CNTs catalysts, a Janus electrode is designed by adjusting the asymmetric wettability to achieve H2O2 productivity of 264.8 mol kgcat–1 h–1.

Melamine sponge templated synthesis of nickel nanoparticles encapsulated in B, N co-doped carbon nanotubes towards the selective electrosynthesis of hydrogen peroxide

“…Therefore, the doping of B causes the charge redistribution resulting in the electron-rich state of the nearby C site, which is conducive to the adsorption of *OOH for improving 2e − ORR. 43 The above DFT calculations confirm that the co-doping of B and N can enhance the activity and selectivity towards 2e − ORR, which is commensurate with the experimental results.…”

Carboxylated Hexagonal Boron Nitride/Graphene Configuration for Electrosynthesis of High‐Concentration Neutral Hydrogen Peroxide

“…CBNO exhibited a clear layered structure (Figure 1C) and a rich lattice stripe. [23] Figure 1C also illustrated a large number of regions where the h-BN coexisted with the graphitized layer. One of the h-BN domains had a d (002) of 0.366 nm and a bright spot in the FFT plot (blue box), while the graphitized region had a d (002) of 0.335 nm and a bright spot (yellow box).…”

Carboxylated Hexagonal Boron Nitride/Graphene Configuration for Electrosynthesis of High‐Concentration Neutral Hydrogen Peroxide

“…In the high‐resolution transmission electron microscopy (HR‐TEM) image, the Fast Fourier Transform (FFT) plot of AC showed a bright halo, reflecting a disordered structure (Figure S3). CBNO exhibited a clear layered structure (Figure 1C) and a rich lattice stripe [23] . Figure 1C also illustrated a large number of regions where the h‐ BN coexisted with the graphitized layer.…”