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Abstract: Several binary sulfides are used for sensing of gases such as NH3, NO2, and H2, but not for H2S, especially at room temperature, because of the relative inactivity of metal sulfide surface bonds for this gas. The situation can be entirely different in the ternary case, however, due to the possible synergy of interactions involving dual cation surface chemistry. This is borne out by the present work wherein the Cu3SnS4 material, the Cu‐rich ternary sulfide used for the first time in the gas sensing context, not only senses H2S at room temperature but also remarkably does so with high selectivity and stability. Thus, a combined experimental and computer modeling study on the use of nanocrystalline orthorhombic Cu3SnS4 phase is reported for H2S sensing. The material shows sensitivity for a wide range of H2S concentrations (from 10 to 2000 ppm). The performance of the sensing device fabricated on Kapton substrate remains intact even after several days and multiple bending cycles. Importantly, these experimental findings are consistent with the results of density functional theory calculations for binding energies for different gases, namely, H2S, NO2, NH3, and CO, on Cu3SnS4 surface. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) water splitting is a sustainable pathway for solar to hydrogen conversion. Graphitic carbon nitride (g‐C3N4) nanosheets have the suitable bandgap and band‐edge energies to act as a visible‐light photocatalyst for water splitting, but the fast recombination of photoexcited electron–hole pair limits the efficiency. Herein, N‐doped few‐layer graphene (NFG) dressed with titanium nitride (TiN) nanocrystals (TiN‐NFG) is introduced as an efficient co‐catalyst which improved the water reduction activity of g‐C3N4 by 16 times. The 2D nanocomposite of g‐C3N4:TiN‐NFG has an extended interface for efficient separation of photoexcited electron–hole pair through electron transfer from g‐C3N4 to TiN‐NFG. The metal‐like electronic structure of TiN in combination with good charge conducting capability of NFG reduces the charge transfer resistance at the electrode/electrolyte interface. Both these aspects are responsible for the enhanced PEC activity leading to a photocurrent density of −196 µA cm−2 at 0.11 V versus reversible hydrogen electrode as a photocathode for the g‐C3N4:TiN‐NFG nanocomposite. The nanocomposite is stable, low cost (free from noble metals), and the extent of enhancement in the PEC efficiency for reduction reaction is remarkable compared to prior literature. An efficient noble metal free co‐catalyst: Titanium nitride embedded few‐layer N‐doped graphene nanosheet (TiN‐NFG) is developed to boost the photoelectrochemical (PEC) reduction of water with graphitic carbon nitride (g‐C3N4). The huge enhancement in PEC activity is achieved owing to extended interface area at the 2D/2D heterojunction of composite promoting the superior separation of photoexcited charges in g‐C3N4. [ABSTRACT FROM AUTHOR]