Abstrak ZnO telah disintesis dengan metode sol-gel menggunakan pengkelat dari ekstrak buah nanas sebagai solusi agardapat mengurangi penggunaan zat kimia. Buah nanas yang digunakan yaitu nanas madu dan nanas batu yangmemiliki kandungan kadar gula total berbeda. Pada nanostruktur ZnO yang menggunakan pengkelat nanas madu disintesis pada suhu kalsinasi 500, 600, 700, 800, dan 900˚C. Nanostruktur ZnO yang menggunakan pengkelatnanas batu berhasil disintesis pada suhu kalsinasi 700 dan 800˚C. Dalam eksperimen ini dipelajari efek suhukalsinasi terhadap hasil nanostruktur ZnO serta pengaruhnya saat diaplikasikan sebagai fotokatalis untukmendegradasi methylene blue. Hasil karakterisasi morfologi dengan SEM sampel menggunakan pengkelatnanas madu di suhu kalsinasi 800˚C diketahui bahwa ukuran partikel berada pada rentang 0,540 – 3,614 μmdengan rata-rata 1,858 μm, hasil yang masih besar diperkirakan terjadi karena adanya aglomerasi. Karakterisasiterhadap sifat kristal dengan menggunakan XRD di dapatkan ukuran kristal pada sampel menggunakanpengkelat nanas madu di suhu kalsinasi 800˚C dengan rata-rata 35,10 nm sementara pengkelat nanas madu disuhu kalsinasi 700˚C, ukuran kristalit yaitu dengan rata-rata 30.90 nm. Kedua sampel yang dikarakterisasi sifatkristalnya dengan menggunakan XRD memiliki struktur kristal wurtzite berbentuk heksagonal yang berukuran a= 3,25 x 10−10 m dan c = 5,21 x 10−10 m.Kata kunci : ZnO, green synthesis, metode sol-gel, degradasi metilen biru, suhu kalsinasi Abstract ZnO has been synthesized by the sol-gel method with chelate from pineapple (Ananas comosus (L.)) extract, asa solution to reduce the chemical substances. Pineapple extract is used as a chelate because it has high totalsugar content. ZnO nanostructure that has been synthesized with cayenne pineapple chelate was synthesized atcalcination temperatures of 500, 600, 700, 800 and 900 ˚C, whereas ZnO nanostructure that has beensynthesized with queen pineapple chelate was synthesized at calcination temperatures of 700 and 800 ˚C. Themorphology of ZnO nanostructure has been checked by Scanning Electron Microscopy (SEM). ZnOnanostructure that has been synthesized with cayenne pineapple chelate at calcination temperature of 800 ˚Cshowed particle size average of 1,858 μm, these result was still too large and occurred due to agglomeration.The crystallite structure of calcined powders were analyzed using XRD. The average size of zno nanostructurecrystallite was synthesized with cayenne pineapple chelate at 800 ˚C calcination temperature, which was 35,10nm while at calcination temperature 700 ˚C the average size of crystallite was 30.90 nm. The diffraction peaks can be indexed as hexagonal wurtzite structure of ZnO (a = 3,25 x 10−10 m, c = 5,21 x 10−10 m) and diffractiondata were in good agreement with the JCPDS card for ZnO (JCPDS 36-1451). The photocatalytic activity ofZnO catalysts obtained by modified sol-gel method at different calcination was valuated for the photodegradation of methylene blue under UV light. The most effective degradation occurred in Zno nanostructurewhich was synthesized with cayenne pineapple as chelate at 700 ˚C calcination temperature during UVirradiation for 240 minutes, the degradation rate was 55,87% at a concentration of 10 ppm MB solution. Keywords: ZnO, green synthesis, sol-gel method, degradation of methylene blue, calcination temperature