Cancer phototherapy (PT) including photodynamic therapy (PDT) and photothermal therapy (PTT) has attracted extensive interest due to its non-invasive and region-specific nature. In order to enhance the efficacy, we have fabricated various nanocomposites consisting of a photosensitizer (chlorin e 6 (Ce6), pheophorbide a (Pa) or bacteriopheophorbide a (bPa)) for PDT and a two-dimensional nanosheet (graphene or MoS2) for PTT by a one-pot protocol through liquid phase exfoliation. In addition, an anticancer drug (doxorubicin (DOX) or irinotecan (Ir)) was loaded on the nanosheet in the same way for comparison. The nanocomposites demonstrated stability when dispersed in water except for MoS2-Ir. We observed that MoS2-Ce6 killed cancer cells over ten times more effectively than other Ce6-loaded nanocomposites.