Cobalt diselenide(CoSe2)hierarchical clew-like structure is synthesized via a dual-surfactant templated hydrothermal process,and for the first time,its microwave absorption capability has been established.Specifically,the as-synthesized hierarchical interconnected structure is assembled by numerous dense nanobelts.Meticulous tuning of the synthetic conditions which could influence the hierarchical architecture indicates that,in this system,cetyltrimethylammonium bromide(CTAB)plays a dominate role of“balling”while protonated diethylenetriamine(DETA)plays the role of“stringing”.As a novel absorbent,the microwave absorption performance of CoSe2 microstructure is evaluated in 2-18 GHz band.Particularly,3D hierarchical CoSe2 microclews exhibit superior minimum reflection loss of-26.93 dB at 7.28 GHz and effective absorption bandwidth of 3.72 GHz,which are～120％and～104％higher than those of simple CoSe2 nanosheets,respectively.Such drastic enhancement could be attributed to the large specific surface area,and more dissipation channels and scattering sites enabled by the unique clew-like microstructure.The versatile dual-surfactant templated assembly of hierarchical CoSe2 microstructure,along with its appreciable dielectric microwave absorption performance,provides new inspirations in developing novel microwave absorbents for mitigation of electromagnetic pollution.