Hierarchically Interlaced 2D Copper Iodide/MXene Composite for High Thermoelectric Performance

A hierarchical layered architecture in thermoelectric materials works as an ad hoc methodology for strengthening the unique inherent properties. Herein, an excellent thermoelectric behavior in novel 2D copper iodide nanoflakes is demonstrated by compositing with Ti 3 C 2 MXene nanoinclusions. The interlaced architecture of the CuI/Ti 3 C 2 composite lifts the electrical conductivity over two orders by efficient charge transport mechanisms. The thermal conductivity of CuI/Ti 3 C 2 composite is reduced by drastic suppression of mid‐ and high‐frequency phonons by interfacial energy barrier scattering. The structural engineering approach yields a massive power factor of 225 μW m −1 K −2 and a figure of merit value of 0.48 in CuI/5 vol% Ti 3 C 2 composite. A straightforward approach of tuning the figure of merit in Earth‐abundant, nontoxic thermoelectric materials to develop future sustainable energy sources is established.