Enhancement of Triboactivity of Nanolamellar Graphitic-C₃N₄ by N-Doped ZnO Nanorods

Abstract

The tribological activity of the synthesized nanosheets of a polymeric graphitic carbon nitride, g-C3N4, was upgraded by introducing hydrothermally synthesized N-doped zinc oxide nanorods. The high-resolution scanning electron microscopy, TEM, and HR-TEM studies of the hybrid (N–ZnO/g-C3N4) reveal that N-doped ZnO nanorods were spread over g-C3N4 nanosheets. The tribological activity of well-characterized nanomaterials was graded in paraffin oil (PO) at an optimized concentration, 0.20% w/v, on a four-ball tester conducting ASTM D4172 and ASTM D5183 tests. According to the observed tribological data, mean wear scar diameter, friction coefficient (COF), and seizure load, nanorods performed much better than the nanosheets. The hybrid exhibited highly advanced activity because of the synergy between noncovalently interacting nanorods and nanosheets. The SEM and AFM analyses of the wear pathway corroborated the tribological results. The energy-dispersive X-ray and X-ray photoelectron spectroscopy studies of the tribofilm confirmed the elemental composition and chemical states of all the elements, respectively. A possible mechanism of lubrication has been presented.

Reinforcement of nanoporous lanthanum-doped zinc borate by vanadium selenide nanosheets for improved tribological activity

“…Moreover, the peaks that appear in the Fe 2p XPS spectrum at 710.5 eV (Fe 2p 3/2 ) and 724.2 eV (Fe 2p 1/2 ), [12][13][14][15][16][17] indicate the formation of Fe 2 O 3 through the oxidation of Fe of the steel. 2,3,5,6 Thus, the presence of various oxides, particularly ZnO, 3 La 2 O 3 , 5 B 2 O 3 , 29 and V 2 O 5 , 52 usually facilitate lubrication and promote the tribological properties of LZB/VSe 2 .…”

“…As a consequence of defects, the electronic structure gets affected due to the formation of slip systems, and ultimately, shear strength is diminished. 3 Undoubtedly, the layered structure of VSe 2 has facilitated the sliding motion due to weak van der Waals forces. 3,5,6 Under thermo-mechanical effects 40 of the tribological test, the nanosheets were squeezed and smeared on the worn surface of the porous LZB matrix due to high contact pressure.…”

“…3 Undoubtedly, the layered structure of VSe 2 has facilitated the sliding motion due to weak van der Waals forces. 3,5,6 Under thermo-mechanical effects 40 of the tribological test, the nanosheets were squeezed and smeared on the worn surface of the porous LZB matrix due to high contact pressure. The drastic friction at the interface is therefore weakened.…”

“…1 Furthermore, for the sustainability of the machine and endurability of its components, 2D nanomaterials have been frequently used as wear and friction-reducing additives to the base lubricating oil. [1][2][3]5,6 Recently, the tribological properties of some metal selenides such as MoSe 2 , WSe 2 , NbSe 2, and monoselenide ZnSe, have been investigated. [7][8][9][10][11][12] heterostructures.…”

“…1,5,45 Furthermore, the composites of the doped nanomaterials with layered materials like graphene, graphitic carbon nitride, molybdenum disulde, and copper phthalocyanine have been proclaimed from our group to manifest exemplary tribological behavior. 1,3,5,6 Considering the above, it engrossed us to synthesize nanoporous zinc borate(ZB), lanthanum doped zinc borate(LZB), lamellar vanadium selenide(VSe 2 ), and use the synthesized VSe 2 to reinforce LZB (LZB/VSe 2 ) for upgrading its tribological behavior. Accordingly, VSe 2 nano-sheets, ZB, LZB, and LZB/VSe 2 were synthesized, and their tribological activity was appraised in paraffin oil (PO) on a four-ball tester machine under ASTM D4172 and ASTM D5183 conditions.…”