04933ntm a2200385 i 4500952014000000952012400140999001700264003000800281005001700289006001900306008004100325020003200366040002300398090002800421100004500449245013700494264003400631264001200665300007100677336002100748336002100769337002500790337002300815338002300838338003000861347002400891500004400915502007000959504004001029520334701069610005904416650004504475650001104520942001604531  00102lcc40718REFa10000b10000cREFd2022-03-30l0oFTKA .U45 2021 r ThesispT000001699r2022-05-19 00:00:00t1w2022-03-30yTHESIS  00102lcc40718REFa10000b10000cREFd2022-03-30l0oCD13017pT000001700r2023-01-30 00:00:00t1w2022-03-30yTHESIS  c96554d96560MY-KuUP20251125110002.0t||||fr|||| 000 0 220330s2021    my a|||frm||| 000 0 eng d  aTHE0009196(Local)qhardback  aUMPbengcUMPerda  aFTKA .U45 2021 r Thesis1 aUmi Rabiatul Ramzilah P. Remli,eauthor.10aPhotocatalytic degradation of methylene blue by cqds based composite derived from watermelon rinds /cUmi Rabiatul Ramzilah P. Remli 1aKuantan, Pahang :bUMP,c2021 4c© 2021  axiii,122 pages :billustrations (some color) ;c30 cm. +e1 CD ROM  atext2rdacontent  atext2rdacontent  aunmediated2rdamedia  acomputer2rdamedia  avolume2rdacarrier  acomputer disc2rdacarrier  atext filebPDF2rda  aFaculty of Civil Engineering Technology  aThesis (Master of Science) -- Universiti Malaysia Pahang – 2021  aIncludes bibliographical references3 aDyes comprise of toxic and complex components and has slow degradation rate. The  presence of dyes components altered the colour of the water and  bring negative effects  not  only  from  aesthetics  value  but  also  reducing  the  sunlight  penetration  into  the  waterbody. It also harmful to aquatic organism and human health if discharge directly  to environment. The effort to remove the methylene blue (MB) from wastewater were  reported  using  numerous  methods  such  as  Fenton  treatment,  ozonation,  membrane  filtration,  coagulation,  adsorption,  and  advanced  oxidation  process.  Recently,  photocatalysis has been conducted in several studies to treat dye wastewater because of  the  complete  mineralization  of  organic  compounds.  Despite  of  that,  the  current  photocatalysis method is still limited due to the  high cost and limited source.  On the  contrary, watermelon rinds (WMR) have been discarded as waste and left untreated in  the environment. Therefore,  to  tackle both environmental issues, this study employed  the WMR as the carbon precursor in the synthesize of carbon quantum dots (CQDs) that  can  be  used  as  photocatalyst  to  treat  the  MB  solution.  Unlike  many  other  carbon  nanomaterials such as carbon nanotubes, graphene oxide and graphene quantum dots,  CQDs are easily and inexpensively synthesized using a cheap and sustainable source of  biomass. Hence, the main objective of this study is to evaluate the feasibility of WMR  used in the synthesize  of CQDs to act as a photocatalyst in degrading the MB solution.  CQDs was incorporated with titanium dioxide TiO2  to enhance the chemical, physical  and  optical  properties  of  TiO2  for  evaluation  of  photocatalytic  degradation  under  artificial light irradiation. All photocatalysts powder were characterized using powder  X-ray  diffractometer  (XRD),  high  resolution  transmission  electron  microscope  (HRTEM), scanning electron microscope (SEM), energy dispersive X-ray spectroscope  (EDX),  Brunauer-Emmett-Teller  (BET)  surface  area  analyzer,  X-ray  photoelectron  spectroscope  (XPS),  UV-visible  light  spectrophotometer  (UV-Vis)  and  Photoluminescence  (PL)  spectra.  Next,  photocatalytic  activity  of  the  prepared  photocatalysts  was  evaluated  by  degrading  MB  under  visible  light  from  xenon  lamp  (500W).  Based  on  the  results,  it  is  feasible  to  synthesize  CQDs  derived  from  WMR  which can be used as solely photocatalyst in photocatalytic degradation of MB. In the  results,  it  is  found  that CQDs  with  0.1  g/L  catalyst  loading  at  5  ppm  has  the  highest  photocatalytic  activity  with  73%  of  MB  removal  compared  to  TiO2  and CQDs-  TiO2 due  to  its  small  surface  area.  In  terms  of  the  percentage,  the  MB  degradation  are  as  follows: CQD >CQD-TiO2>TiO2  with 73%, 55% and 27% respectively. The result for  pH of concentration showing that the degradation efficiency increases with increasing  of pH. The catalysts work better in pH 9 due to the cationic property of MB. The kinetic  data  of  MB  degradation  were  fitted  with  Langmuir-  Hinshelwood  kinetic  model  and  kinetic  parameters  were  obtained.  In  conclusion,  this  study  suggested  that  the  concentration of MB can be reduced by utilizing CQDs derived from WMR20aFaculty of Civil Engineering TechnologyxDissertations 0aUniversities and collegesxDissertations 0aTheses  2lcccTHESIS