Powdered-photocatalysis　of　organic　wastewater　is　widely　investigated,　unfortunately　not　industrially　implemented　due　to　its　high　energy　requirement.　Interestingly,　such　issue　may　be　alleviated　via　the　elimination　of　mechanical　stirring　required.　Core-shell　ZnO-based　photocatalysts　were　developed　herein,　subsequently　demonstrated　efficient　photocatalytic　activities　in　the　absence　of　mechanical　stirring.　Results　show　that　the　developed　SiO2-cored　ZnO　photocatalyst　are　highly　crystalline,　while　significantly　smaller　than　coreless,　pure　ZnO　due　to　the　multi-point　crystallization　prompted.　Additionally,　it　is　also　inherited　with　considerable　buoyancy　ability　from　SiO2-core　in　the　absence　of　mechanical　stirring,　concurrently　rendered　with　UV-active　properties　due　to　its　ZnO-shell.　Experimentally,　55%　of　particles　of　ZnO_0.0025　(0.0025　mol　of　ZnO-deposition)　were　found　stably　suspended　for　60　min　in　liquid　substrate,　as　opposed　to　the　instant-settling　of　pure　ZnO　particles.　In　term　of　photocatalytic　activity,　ZnO_0.01　manifested　the　best　methylene　blue　(MB)　degradation　with　150　mL/min　of　O2-bubbling.　67.63%　of　MB　was　degraded　with　photocatalyst　loading　of　0.2　g/L　after　120　min　UV-irradiation,　simultaneously　recorded　the　highest　pseudo-first　order　reaction　constant　of　9.636　×　10−3　min−1.　As　summary,　the　auto-suspending　photocatalysis　conceptualized　in　current　study　offers　a　high　possibility　in　reducing　energy　requirement　for　photo-treatment　of　wastewater,　hence　advocating　its　industrialization　potential　in　near　future.　©　2020　Elsevier　B.V.