Boosting the Faraday Efficiency of Electrochemical Ammonia Synthesis via the Strain Effect Induced by Interfacial Hybrid Formation between BN and Carbon Nanotubes

The electrochemical nitrogen reduction reaction (eNRR) is a highly promising alternative to the Haber–Bosch (H–B) process, but its commercial development is limited by the high bond energy of N2 molecules and the presence of the competitive hydrogen evolution reaction (HER). Here, a metal-free composite electrocatalyst of boron nitride (h-BNNs) and carbon nanotubes (CNTs) was explored through the interfacial hybridization of h-BNNs and CNTs, which showed a highly improved eNRR Faraday efficiency (FE) of 63.9% and an NH3 yield rate of 36.5 μg h–1 mgcat.–1 at −0.691 V (vs RHE). New chemical bonds of C–B and C–N were observed, indicating a strong interaction between CNTs and h-BNNs. According to the Raman spectra and the optimized model of h-BNNs/CNTs, an obvious strain effect between h-BNNs and CNTs was supposed to play a significant role in the highly improved FE, compared with the FE of h-BNNs alone (4.7%). Density functional theory (DFT) calculations further showed that h-BNNs/CNTs had lower energy barriers in eNRR, giving them higher N2 to NH3 selectivity, while h-BNNs have lower energy barriers in the HER. This work shows the important role of the strain effect in boosting the selectivity in the eNRR process

Temporal distribution of onsets of scrub typhus cases in Jingjiang City.

Temporal distribution of onsets of scrub typhus cases in Jingjiang City.</p

Scrub typhus study site: Jingjiang City, Jiangsu Province, China.

Scrub typhus study site: Jingjiang City, Jiangsu Province, China.</p

PCR and ELISA results of 187 cases.

<p>PCR and ELISA results of 187 cases.</p

Phylogenetic analysis based on the <i>O</i>. <i>tsutsugamushi</i> 56-kDa TSA gene.

<p>All the sequences of <i>O</i>. <i>tsutsugamushi</i> in this study marked with black triangles, were compared with other reference sequences available in GenBank. The MEGA 4.0 software was used for the phylogenetic analysis. The stability of the nodes was assessed using neighbor-joining cluster analysis with 1,000 bootstrap replications, and only bootstrap values.70% are shown at the nodes.</p

Demographic characteristics of the scrub typhus cases and controls that were enrolled in the study.

<p>Demographic characteristics of the scrub typhus cases and controls that were enrolled in the study.</p

Clinical and laboratory findings for scrub typhus cases of Jinjiang City.

<p>Clinical and laboratory findings for scrub typhus cases of Jinjiang City.</p

Single- and multiple-variable conditional logistic regression analyses for identifying risk factors for scrub typhus.

<p>Single- and multiple-variable conditional logistic regression analyses for identifying risk factors for scrub typhus.</p