# Fast and selective room-temperature hydrogen sensing of oxygen-deficient orthorhombic Nb2O5 nanobelts

## TL;DR

Researchers developed a new hydrogen sensor using nanobelts that can detect hydrogen quickly and accurately at room temperature.

## Contribution

The study introduces oxygen-deficient orthorhombic Nb2O5 nanobelts for efficient room-temperature hydrogen sensing.

## Key findings

- Nb2O5 nanobelts with optimal oxygen vacancies achieved a sensor response of 10.3 to 5000 ppm hydrogen.
- The sensor response time was as low as 28 seconds.
- The sensor showed good selectivity against interference gases.

## Abstract

The increasing demand for hydrogen as a clean and renewable energy source necessitates the development of efficient and reliable hydrogen sensing technologies. This study presents the preparation of oxygen-deficient orthorhombic Nb2O5 nanobelts for room-temperature chemiresistive hydrogen sensing. The nanobelts were synthesized by converting the H3ONb3O8 nanobelts into orthorhombic Nb2O5 through a calcination-based topochemical transformation process. The content of oxygen vacancy defects in the nanobelts was effectively modified by post-annealing treatments, without introducing undesirable phase transition. The results revealed that the hydrogen sensing performance of Nb2O5 nanobelts is closely linked to the oxygen vacancy content. With optimal defect concentration, the proposed chemiresistive sensors demonstrated significantly enhanced room-temperature hydrogen response, achieving a sensor response of 10.3 and response time down to 28 s, to 5000 ppm hydrogen. The sensor also exhibited good selectivity against various interference gases, highlighting its great potential for fast and accurate hydrogen leak detection in practical applications.

Fast, sensitive and selective room-temperature hydrogen sensing is achieved by utilizing oxygen-deficient orthorhombic Nb2O5 nanobelts.