Advanced　thermal　barrier　coatings　(TBCs)　with　better　thermal　barrier　performance　are　required　by　both　advanced　gas　turbine　and　air　engine.　In　this　work,　novel　bimodal　TBCs　with　low　thermal　conductivity　were　deposited　and　characterized　by　a　novel　co-spray　approach　with　both　solid　powder　and　suspension.　Experimental　and　finite　element　analyses　were　used　to　optimize　the　process　parameters　to　prepare　the　specific　morphology　nanostructure　features.　With　a　comprehensive　understanding　on　the　influence　of　spraying　parameters　on　the　morphology　of　nano-particles,　homogeneous　nano-particle　heaps　with　a　large　aspect　ratio　were　introduced　to　conventional　layered　coatings　by　plasma　co-spraying　with　suspension　and　solid　powder.　Co-sprayed　bimodal　microstructure　composite　coatings　resulted　from　both　wet　suspension　droplets　and　molten　particle　droplets　exhibited　low　thermal　conductivity.　The　thermal　conductivity　of　the　composite　coating　was　1/5　lower　than　that　of　the　counterpart　coatings　by　conventional　plasma　spraying　with　solid　powder.　This　study　sheds　light　to　the　structural　tailoring　towards　the　advanced　TBCs　with　low　thermal　conductivity.　(C)　2017　Published　by　Elsevier　Ltd　on　behalf　of　The　editorial　office　of　Journal　of　Materials　Science　&　Technology.