A quantum spin liquid (QSL) is an exotic state of matter, which shows no magnetic order down to zero temperature but the spins are highly entangled. Its elementary excitations are fractional spinon excitations that show continuous spectra in neutron experiments. Experimental evidence has been found in 2D triangular-lattice YbMgGaO4, displaying dispersive spinon excitations with a clear upper edge. Here, we propose to study its isostructural compound TmMgGaO4 single crystals, which present paramagnetic behavior with Curie-Weiss temperature of around -20 K, indicating a stronger magnetic interaction than YbMgGaO4. Moreover, its non-Kramers doublet ground state can lead to a different spin Hamiltonian and a different topological structure can be expected. Thus, it is rather interesting to study the potential spinon excitations in TmMgGaO4 to provide another testing ground for QSL studies.