The special shape hollow spheres and the corresponding TEM images.
► The special shape hollow g-C3N4 nanospheres synthesized by the solvothermal technique. ► The hollow nanospheres deform easily other than break under suffering from the external pressure. ► The product might have potential application in gas storage, drug delivery, catalysts and catalyst etc. ► The hollow g-C3N4 nanospheres may have potential applications as the optical materials.