A selective cataluminescence sensor with a homemade gaseous sample introduction system for accurate and sensitive determination of H2S using catalytic g-C3N4@Fe

•The g-C3N4@Fe was firstly used as the catalyst for cataluminescence (CTL)-based sensing for H2S.•A home-designed system was developed for reliable preparation and introduction of H2S samples.•The sensing performance was comparable to or better than previous works on CTL-based sensing for H2S.•The method was applicable for home-made real samples with high accuracy. A home designed cataluminescence (CTL)-based gas sensor was developed with high selectivity and sensitivity, using g-C3N4@Fe composite as the catalyst for the detection of hydrogen sulfide (H2S) in a controllable manner. Intensive CTL was generated due to the effectively catalytic oxidation of H2S on the surface of the g-C3N4@Fe but none from diverse possible gas interferents including other sulfides or thiols, which was also proportional in intensity to the H2S concentration. The prepared g-C3N4@Fe was thoroughly characterized by TG, FTIR, XRD, SEM, XPS and TEM, and the sensing parameters were optimized. It turned out that 0.36% Fe contained in the g-C3N4 could lead to the most intensive CTL from H2S, with a linear range of 10–500 μmol•mol−1 (i.e. ppm) and a limit of detection 1.5 μmol•mol−1. The proposed method also showed other attractive features including rapidness, simple equipment and low cost.