Two-dimensional BiP3 with high carrier mobility and moderate band gap for hydrogen generation from water splitting

[Display omitted] •Two structures of BiP3 monolayere with C2/m and P3m1 are predicted.•P3m1 structure is a candidate of photocatalytic water splitting to produce hydrogen.•The highest mobility of BiP3 monolayers is large than previous XP3 monolayers.•Band structures and absorptions of BiP3 monolayers can be tuned with strain. The monolayered bismuth triphosphide (BiP3) with C2/m and P3m1 space groups are predicted as a new body of the 2D triphosphide structures by using the first principles calculations. The results demonstrate that the BiP3 monolayers possess indirect bandgaps of 1.36 and 2.20 eV (HSE06) or 1.34 and 2.64 eV (G0W0). The band edges of the monolayer of P3m1 BiP3 can straddle the reduction and oxidation potentials of the water splitting reaction of hydrogen production even under the uniaxial or biaxial strain from −2% to 1%. Moreover, the highest mobility of 2.49 × 105 cm2 V−1 s−1 for the hole of the P3m1 BiP3 monolayer is larger than the previously reported values of triphosphide monolayers. The obvious absorptions in the visible light range are observed for both BiP3 monolayers and that of the P3m1 structure can be improved by the tensile strain. Therefore, the P3m1 BiP3 monolayer is a promising candidate of the photocatalytic materials for the water splitting reaction to produce hydrogen under driven by the visible light.