Side-by-side design of bi-component heterojunction nanofibers for high-performance gas sensors: Improvement in synergistic effect

[Display omitted] •Side-by-side bi-component heterojunctional nanofibers (SBHNFs) were designed via V-channel electrospinning technique.•The sensors based on In2O3/NiO (INO) SBHNFs show a high response of 210.44 towards 100 ppm ethanol at 260 °C.•The INO SBHNF sensors also show a fast response/recovery towards ethanol with an excellent stability and a good selectivity.•The side-by-side design in heterojunctions is the main enhancement factor for the response and response/recovery rate. Heterojunctions are often introduced into gas sensor electrodes due to they can lower the working temperature and increase response rate during gas-sensing detection. However, many reported core–shell structured heterojunctions show a bad synergistic enhancement effect from both components. Here, a type of side-by-side bi-component heterojunction nanofibers of NiO/In2O3 (INO SBHNFs) was designed by the self-made V-channel electrospinning technique. Results showed that these SBHNFs are comprised of two component NFs that attach together side-by-side with a well-defined interface. And the sensors based on INO-10 SBHNFs show the highest response of 210 to 100 ppm ethanol at 260 °C, which is an order of magnitude higher than all those of the ones based on the In2O3 and INO-10-C NFs. Moreover, the INO-10 SBHNF sensors also show a high response recovery rate (4 s/36 s) and a low limit of detection (