| dc.description.abstract | In this study, several stages of work have been carried out, that is the synthesis
of nitrogen doped carbon dots (CDs), nitrogen doped zink oksida (N-ZnO) and N-ZnO
/CDs as photocatalysts in photodegradation of organic pollutants methylene blue
(MB). In the first stage, the synthesis of CDs was carried out using soybean as a
precursor and ethylenediamine as nitrogen doping using the hydrothermal method at a
temperature of 180oC for 8 hours. In the second stage, N-ZnO synthesis was carried
out using urea as a nitrogen dopant with a calcination method at a temperature of 500oC
for 2 hours in air (N2) condition and heating rate of 5
oC/min. The calcination
temperature is determined from the results of the TGA analysis. In the third stage, the
synthesis process of N-ZnO/CDs nanocomposites was carried out using a simple one
method with concentration ratio of 2: 1. The results of this study show that CDs have
been successfully synthesized which is confirmed from the results of HR-TEM, which
shows that CDs are spherical with a particle size of 4,249 nm. Based on the
caharacterization results of XRD and HR-TEM, N-ZnO and N-ZnO/CDs
nanocomposites have a hexagonal wurtzite structure. The materials N-ZnO and N ZnO/CDs nanocomposites also experienced an increase in photocatalyst
characteristics such as adsorption in the visible beam region, having a mikroporous
structure, with a small Eg value of N-ZnO (2.78eV), N-ZnO/CDs (2.45 eV) and
surface area (SBET) N-ZnO (3.827 m2
/g), N-ZnO/CDs (3.757 m2
/g). In the fourth stage
photocatalyst CDs, N-ZnO and N-ZnO/CDs were used in methylene blue
photodegradation under UV B light radiation for 60 min. Photocatalysts of
nanocomposites N-ZnO/CDs showed the highest photodegrading effectivity of 83.4%
with a degradation rate k= 0.0202 min-1
. This is evidenced from UV-Vis and PL data
which explains that N dopant in ZnO forms p-type semiconductors, as well as the
addition of CDs which act as energy transfer and photosensitizers so as to reduce and
prevent electron-hole recombination. From this study, it was concluded that N ZnO/CDs nanocomposites can be an ideal photocatalyst material for the degradation
of methylene blue organic liquid waste. | en_US |
