Synthesis of hierarchical Ni3S2@NiMoO4 core-shell nanosheet arrays on Ni foam for high-performance asymmetric supercapacitors

Low-crystalline nickel hydroxide nanosheets embedded with NiMoO4 nanoparticles on nickel foam for high-performance supercapacitor applications

“…The effect of the urea concentration on the composition and structure of NiMo-LDH was further explored. In the absence of urea (CH 4 N 2 O), Ni(NO 3 ) 2 ·6H 2 O and Na 2 MoO 4 ·2H 2 O are mixed in the hydrothermal reaction, and NiMoO 4 is formed as: 39,40 Na 2 MoO 4 ·2H 2 O + Ni(NO 3 ) 2 ·6H 2 O → NiMoO 4 + 2NaNO 3 + 8H 2 OWhen urea is mixed with Ni(NO 3 ) 2 ·6H 2 O and Na 2 MoO 4 ·2H 2 O, the formation mechanism of Ni(OH) 2 ·0.75H 2 O follows 2 steps: first, under the hydrothermal condition (110 °C), urea can be decomposed according to eqn (2): 41 CO(NH 2 ) 2 + 3H 2 O → 2NH 4 + + CO 2 + 2OH − This is then reacted with nickel ions in the presence of hydroxyl ions to form Ni(OH) 2 ·0.75H 2 O:Ni 2+ + 2OH − + 0.75H 2 O → Ni(OH) 2 ·0.75H 2 OAt the same time, molybdate ions can readily react with nickel ions under the hydrothermal condition to form NiMoO 4 (eqn (1)). So, the dried final product is composed of a mixture of Ni(OH) 2 ·0.75H 2 O and NiMoO 4 phases.…”

Recent developments and future perspectives on energy storage and conversion applications of nickel molybdates

“…Hydrothermal synthesis covers the largest share of exertions witnessed for the preparation and modulation of properties of NiMoO 4 28,32,54,63,65,69,74,75,77,78,123,161,165,166,168,170‐173,179,183,184,187,192‐194,198,200,202,206,210‐212,214,215,229,231‐234,256,258‐263,265‐268,270,271,273,275,279‐281,284,286‐288,290,291,294‐298,301,303,305‐313,315‐319,322,324,327‐331,333‐335,337,339‐347,349,352,353,356,358‐360,363‐366,368,370‐374,376‐380 . Typically, it includes a host of strategies towards crystallizing substances from high‐temperature watery mixtures at high vapor pressures.…”

“…Template synthesis is a technique using a nanoporous sheath as a pattern to form nanofibers from various substances, namely, metals, carbon, conductive polymers, and semiconductors 383,384 . There are a number of open literature which states adaptation of template synthesis for fabrication of NiMoO 4 heterostructures 54,63,72,78,108,158,168,210,231,259,263,264,269,274,281,294,297,299,302,316‐318,320,332,339,342,350,358,366,369,373,384‐393 . For instance, Li et al advanced a facile hydrothermal route to develop crystalline NiMoO 4 nanosheets on reduced graphene oxide sheets 384 .…”

“…383,384 There are a number of open literature which states adaptation of template synthesis for fabrication of NiMoO 4 heterostructures. 54,63,72,78,108,158,168,210,231,259,263,264,269,274,281,294,297,299,302,[316][317][318]320,332,339,342,350,358,366,369,373,[384][385][386][387][388][389][390][391][392][393] For instance, Li et al advanced a facile hydrothermal route to develop crystalline NiMoO 4 nanosheets on reduced graphene oxide sheets. 384 In order to create a composite with a big surface area and plenty of mesopores for quick transportation of electrons and ions with the intention of use as a supercapacitor electrode material, the "sheet on sheet" nanostructures are connected to one another (Figure 22).…”

“…This is so because this strategy offers the most convenient processes and yet conducive outcomes. Table 6 is to impart a brief account of a host of developments in catalytic properties of NiMoO 4 done involving heterostructures and hybrids 121,123,256‐382 . in many cases, doping, defect and/or morphology engineering have been amalgamated with the heterostructure for superior enhancement in catalytic properties either to generate more surface area or more population of active sites or for other special necessities as summarized in Table 6.…”