In the present study, novel Co3O4/NiO nanosponges designed for the photocatalytic degradation of organic contaminants were synthesized by a simple precipitation technique. The formation of sponge-like nanostructures was clearly evident through the TEM analysis. The photocatalytic efficiency was tested against rhodamine B (RhB) and congo red (CR) dye solutions. Co3O4/NiO nanosponges showed excellent and enhanced photocatalytic efficacy compared to those of Co3O4, NiO nanoparticles, and standards like TiO2 and ZnO. The influence of paramount important operational parameters was explored and the conditions for the best photocatalytic efficiency were optimized. The trapping experiment revealed that the reactive oxygen species (ROS) identified was ·OH radical. These findings certainly open up a new way for synthesizing a morphology dependent photocatalyst.
Tan G, Zhang L, Ren H , et al.. Effects of pH on the hierarchical structures and photocatalytic performance of BiVO4 powders prepared via the microwave hydrothermal method. ACS Applied Materials & Interfaces, 2013, 5(11): 5186–5193 https://doi.org/10.1021/am401019m
pmid: 23668183
2
Lei W, Portehault D, Dimova R , et al.. Boron carbon nitride nanostructures from salt melts: tunable water-soluble phosphors. Journal of the American Chemical Society, 2011, 133(18): 7121–7127 https://doi.org/10.1021/ja200838c
pmid: 21506566
3
Richardson S D . Water analysis: emerging contaminants and current issues. Analytical Chemistry, 2009, 81(12): 4645–4677 https://doi.org/10.1021/ac9008012
pmid: 19456142
4
Latha P, Dhanabackialakshmi R, Kumar P S , et al.. Synergistic effects of trouble free and 100% recoverable CeO2/Nylon nanocomposite thin film for the photocatalytic degradation of organic contaminants. Separation and Purification Technology, 2016, 168: 124–133 https://doi.org/10.1016/j.seppur.2016.05.038
5
Babu S G, Vinoth R, Narayana P S , et al.. Reduced graphene oxide wrapped Cu2O supported on C3N4: An efficient visible light responsive semiconductor photocatalyst. APL Materials, 2015, 3(10): 104415 https://doi.org/10.1063/1.4928286
6
Nezamzadeh-Ejhieh A , Banan Z . Sunlight assisted photodecolori-zation of crystal violet catalyzed by CdS nanoparticles embedded on zeolite A. Desalination, 2012, 284: 157–166 https://doi.org/10.1016/j.desal.2011.08.050
7
Bhatnagar A, Hogland W, Marques M , et al.. An overview of the modification methods of activated carbon for its water treatment applications.Chemical Engineering Journal, 2013, 219:499–511 https://doi.org/10.1016/j.cej.2012.12.038
8
Khabashesku V N , Zimmerman J L , Margrave J L . Powder synthesis and characterization of amorphous carbon nitride. Chemistry of Materials, 2000, 12(11): 3264–3270 https://doi.org/10.1021/cm000328r
9
Zhang X, Wu F, Deng N . Efficient photodegradation of dyes using light-induced self assembly TiO2/β-cyclodextrin hybrid nanoparticles under visible light irradiation. Journal of Hazardous Materials, 2011, 185(1): 117–123 https://doi.org/10.1016/j.jhazmat.2010.09.005
pmid: 20880630
10
Fan H J, Lu C S, Lee W L W, et al.. Mechanistic pathways differences between P25-TiO2 and Pt-TiO2 mediated CV photodegradation. Journal of Hazardous Materials, 2011, 185(1): 227–235 https://doi.org/10.1016/j.jhazmat.2010.09.022
pmid: 20943313
11
Ahmad R. Studies on adsorption of crystal violet dye from aqueous solution onto coniferous pinus bark powder (CPBP). Journal of Hazardous Materials, 2009, 171(1–3): 767–773 https://doi.org/10.1016/j.jhazmat.2009.06.060
pmid: 19604639
12
Fujishima A, Honda K. Electrochemical photolysis of water at a semiconductor electrode. Nature, 1972, 238(5358): 37–38 https://doi.org/10.1038/238037a0
pmid: 12635268
13
Kamat P V. Photochemistry on nonreactive and reactive (semiconductor) surfaces. Chemical Reviews, 1993, 93(1): 267–300 https://doi.org/10.1021/cr00017a013
14
Hu Y, Gao X, Yu L , et al.. Carbon-coated CdS petalous nanostructures with enhanced photostability and photocatalytic activity. Angewandte Chemie International Edition, 2013, 52(21): 5636–5639 https://doi.org/10.1002/anie.201301709
pmid: 23564707
15
Chen X, Shen S, Guo L , et al.. Semiconductor-based photocatalytic hydrogen generation. Chemical Reviews, 2010, 110(11): 6503–6570 https://doi.org/10.1021/cr1001645
pmid: 21062099
Bandara J, Yasomanee J P. p-Type oxide semiconductors as hole collectors in dye-sensitized solid-state solar cells. Semiconductor Scienceand Technology, 2007, 22(2): 20–24 https://doi.org/10.1088/0268-1242/22/2/004
18
Shi J, Guo L. ABO3-based photocatalysts for water splitting. Progress in Natural Science: Materials International, 2012, 22(6): 592–615 https://doi.org/10.1016/j.pnsc.2012.12.002
19
Wan X, Yuan M, Tie S L , et al.. Effects of catalyst characters on the photocatalytic activity and process of NiO nanoparticles in the degradation of methylene blue. Applied Surface Science, 2013, 277: 40–46 https://doi.org/10.1016/j.apsusc.2013.03.126
20
Fominykh K, Chernev P, Zaharieva I , et al.. Iron-doped nickel oxide nanocrystals as highly efficient electrocatalysts for alkaline water splitting. ACS Nano, 2015, 9(5): 5180–5188 https://doi.org/10.1021/acsnano.5b00520
pmid: 25831435
21
Babu S G, Vinoth R, Kumar D P , et al.. Influence of electron storing, transferring and shuttling assets of reduced graphene oxide at the interfacial copper doped TiO2 p-n heterojunction for increased hydrogen production. Nanoscale, 2015, 7(17): 7849–7857 https://doi.org/10.1039/C5NR00504C
pmid: 25853995
22
Rubio-Marcos F, Manzano C V, Reinosa J J, et al.. Mechanism of Ni1−xZnxO formation by thermal treatments on NiO nanoparticles dispersed over ZnO. The Journal of Physical Chemistry C, 2011, 115(28): 13577–13583 https://doi.org/ 10.1021/jp201795y
23
Singh S A, Vemparala B, Madras G . Adsorption kinetics of dyes and their mixtures with Co3O4–ZrO2 composites. Journal of Environmental Chemical Engineering, 2015, 3(4): 2684–2696 https://doi.org/10.1016/j.jece.2015.09.029
24
Wang G, Shen X, Horvat J , et al.. Hydrothermal synthesis and optical, magnetic, and supercapacitance properties of nanoporous cobalt oxide nanorods. The Journal of Physical Chemistry C, 2009, 113(11): 4357–4361 https://doi.org/10.1021/jp8106149
25
Salavati-Niasari M , Mir N, Davar F. Synthesis and characterization of Co3O4 nanorods by thermal decomposition of cobalt oxalate. Journal of Physics and Chemistry of Solids, 2009, 70(5): 847–852 https://doi.org/10.1016/j.jpcs.2009.04.006
26
Prakash K, Kumar P S, Saravanakumar K, et al.. Controllable synthesis of SnO2 photocatalyst with superior photocatalytic activity for the degradation of methylene blue dye solution. Journal of Experimental Nanoscience, 2016, 11(14): 1138–1155 https://doi.org/10.1080/17458080.2016.1188222
27
Narayan R V, Kanniah V, Dhathathreyan A . Tuning size and catalytic activity of nano-clusters of cobalt oxide. Journal of Chemical Sciences, 2006, 118(2): 179–184 https://doi.org/10.1007/BF02708470
28
Zhang Y, Liu Y, Fu S , et al.. Morphology-controlled synthesis of Co3O4 crystals by soft chemical method. Materials Chemistry and Physics, 2007, 104(1): 166–171 https://doi.org/10.1016/j.matchemphys.2007.03.003
29
Kumar P S, Karuthapandian S, Umadevi M , et al.. Light induced synthesis of Sr/CdSe nanocomposite for the highly synergistic photodegradation of methylene blue dye solution. Materials Focus, 2016, 5(2): 128–136 https://doi.org/10.1166/mat.2016.1301
30
Kumar P S, Selvakumar M, Babu S G , et al.. CdO nanospheres: Facile synthesis and bandgap modification for the superior photocatalytic activity. Materials Letters, 2015, 151: 45–48 https://doi.org/10.1016/j.matlet.2015.03.047
31
Kumar P S, Selvakumar M, Babu S G , et al.. CuO/ZnO nanorods: An affordable efficient p-n heterojunction and morphology dependent photocatalytic activity against organic contaminants. Journal of Alloys and Compounds, 2017, 701: 562–573 https://doi.org/10.1016/j.jallcom.2017.01.126
32
Karthik P, Vinoth R, Babu S G , et al.. Synthesis of highly visible light active TiO2-2-naphthol surface complex and its application in photocatalytic chromium(VI) reduction. RSC Advances, 2015, 5(50): 39752–39759 https://doi.org/10.1039/C5RA03831F
33
Kumar P S, Selvakumar M, Bhagabati P , et al.. CdO/ZnO nanohybrids: facile synthesis and morphologically enhanced photocatalytic performance. RSC Advances, 2014, 4(62): 32977–32986 https://doi.org/10.1039/C4RA02502D
34
Karunakaran C, Senthilvelan S, Karuthapandian S . Solar photooxidation of aniline on ZnO surfaces. Solar Energy Materials and Solar Cells, 2005, 89(4): 391–402 https://doi.org/10.1016/j.solmat.2005.01.008
35
Saravanakumar K, Kumar P S, Kumar J V, et al.. Controlled synthesis of plate like structured MoO3 and visible light induced degradation of rhodamine B dye solution. Energy and Environment Focus, 2016, 5(1): 50–57 https://doi.org/10.1166/eef.2016.1192
