Very recently, a two-dimensional (2D) biphenylene carbon network, named as bi-C here, has received many attentions. In this work, we identified a 2D biphenylene GeS, named as bi-GeS, and its seven counterparts. For bi-GeS, examination of the stability shows that it meets the requirements of dynamical, thermal and mechanical stabilities. Analyses of the electronic properties suggest that bi-GeS monolayer, bilayer and trilayer retain semiconducting properties with suitable band edge alignments of water splitting. In particular, distinct charge separations are found in bi-GeS bilayer and trilayer. Besides, our studies bore out that its seven counterparts, including bi-P, bi-As, bi-GeSe, bi-SnS, bi-GaS, bi-GaSe and bi-InSe, are also dynamically stable. Further studies revealed that they also have opportune redox levels of water splitting. Our results tremendously enriched 2D biphenylene family and provided many potential maquettes for the photocatalytic application.