Rational design of LaSrCoO4/LaCoO3/MWCNT nanocomposites with boosted electrochemical hydrogen storage capability: Tripodal tetraamine ligand-assisted synthesis, characterization, and optimization

• In-situ coupling strategy for the preparation of mixed 214- type LaSrCoO 4 /113- type LaCoO 3 (LSCO) nanostructures via tris (2-aminoethyl) amine based tripodal ligands. • Evaluation of tripodal chelating ligand’s structures on the structural integrity and morphological properties of LSCO. • Loading of MWCNTs in LSCO composites was optimized for the best hydrogen storage performance. • LSCO/MWCNT1.0% nanocomposites achieved highest discharge capacity of 1800.27 mAh g −1 for 16th cycle. The originality of present investigation is in-situ preparation of 214-type LaSrCoO 4 and 113-type LaCoO 3 nanostructures through a tripodal tetraamine ligand-assisted templating mechanism, for the first time. Controlling the combustion conditions of nano hetero-structured LaSrCoO 4 /LaCoO 3 (LSCO) on the composition, morphology, and crystallinity features was elaborated with tris (2-aminoethyl) amine-based ligands having different molecules of pods/arms, such as 2'-hydroxyacetophenone ( L 1 ), 2',6'-dihydroxyacetophenone ( L 2 ), and 3-indolcarbaldehyd ( L 3 ). Crystallographic information from Rietveld refinement and observation studies illustrated minimal agglomeration and more crystalline LSCO products in L 3 ligand-assisted reaction, yielding binary phase systems of tetragonal LaSrCoO 4 (60.24%) and rhombohedral LaCoO 3 (39.76%) with mean particle diameter of 65.62 nm. In this line, structural integrity and electrochemical hydrogen storage capability of resulting LSCO nanoparticles was developed with inclusion of conductive carboxylated multi-walled carbon nanotubes (MWCNT-COOH) linkers. The remarkable discharge capacity in electrochemical hydrogen storage was found for LSCO/MWCNT1.0% nanocomposites (1800.27 mAh g −1 ) after continuously 16 cycles at a current of 1 mA as compared to L 3 -assisted auto-combustion synthesized LSCO (808.33 mAh g −1 ), 2.0%- (1540.27 mAh g −1 ) and 3.0%- (1386.66 mAh g −1 ) MWCNT reinforced composite electrodes in 2.0 M KOH electrolyte. The intertwined LSCO/MWCNT nanocomposite support the running of simple self-assembly approach for future high-performance energy storage devices.