abstract
Vertically aligned carbon nanotubes (VA-CNTs) of 2.3 mu m in height were produced by thermal chemical vapor deposition (TCVD) on Si/SiO2 substrates. These carbon arrays were coated with zinc oxide (ZnO) via atomic layer deposition (ALD) technique. Conformal, uniform and very thin films (max. 26 nm) around the CNTs were obtained after 200 ALD cycles. The photocatalytic performance of these nanocomposite materials was tested in the degradation of rhodamine B, a harmful dye present in food and textile wastewaters. The optimal degradation performance is already obtained after 100 ALD cycles on VA-CNTs, which provide 77 % of RhB degradation after 420 min of irradiation. The photocatalytic results suggested a remarkable synergistic effect between the CNT and ZnO phases. The stability of ZnO/CNTs nanocomposites after being used as photocatalysts was demonstrated by Raman spectroscopy, as the CNTs structure stayed intact and the ZnO remained coupled to the CNTs. Thus, a main advantage of the present approach is the immobilization of the photocatalyst material on a solid support, avoiding further complex nanomaterial separation from the treated water stream.
keywords
ATOMIC LAYER DEPOSITION; CARBON NANOTUBES; GROWTH-MECHANISM; DEGRADATION; COMPOSITES; PHENOL; ZNO; PHOTODEGRADATION
subject category
Chemistry
authors
Oliveira, IE; Silva, RM; Girao, AV; Faria, JL; Silva, CG; Silva, RF
our authors
Ana Violeta Girão
Junior Researcher
Ricardo Manuel Fonseca Lopes da Silva
Junior Researcher
Rui Ramos Ferreira e Silva
Associate Professoracknowledgements
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020, financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement and the scientific collaboration from the Associate Laboratory LSRE-LCM - UIDB/50020/2020 - funded by national funds through FCT/MCTES (PIDDAC). C. G. Silva acknowledges the FCT Investigator Programme (IF/00514/2014) with financing from the European Social Fund (ESF) and the Human Potential Operational Programme. This work is funded by national funds (OE), through FCT, I.P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19.