Unique　trimetallic　organic　material　(TMOM)-based　nanostructures　combined　with　the　new　architectures　of　metal–organic　frameworks　(MOFs)　are　promising　candidates　for　gas-sensing　applications.　This　work　is　the　first　to　successfully　convert　MOF　nanomaterials　into　nano-porous　carbon　through　carbon　nanotubes　(CNT)　catalytic　reaction　via　a　simple　and　facile　hydrothermal　method.　The　leaf-like　nanostructures　exhibit　a　high　surface-to-volume　ratio　of　363　m2　g−1.　The　TMOM　nanostructures　were　subsequently　exposed　to　different　types　of　target　gases　for　a　wide　range　of　gas　concentrations　at　different　operating　temperatures.　The　carbon　nanotubes　(TMOM-CNT)　hybrid　nanocomposites　were　characterized　using　X-ray　powder　diffraction,　X-ray　photoelectron　spectroscopy,　Brunauer–Emmett–Teller,　scanning　electron　microscopy,　energy　dispersion　spectrum　analysis,　thermo-gravimetric　analysis,　and　transmission　electron　microscopy.　The　fabricated　Zn-Co-Ni　MOF@CNT　sensors　exhibit　high　selectivity　and　gas-sensing　response　toward　H2S　gas　at　an　optimal　temperature　of　325　°C　for　100　ppm.　These　superior　gas-sensing　performances　reveal　that　the　Zn-Co-Ni　MOF@CNT　sensors　with　a　unique　leaf　shape　exhibit　potential　applications　for　the　environment　applications　in　gas　sensor　industry.　©　2020　Elsevier　B.V.