The first and low cost copper Schiff base/manganese oxide bio nanocomposite from unwanted plants as a robust industrial catalyst

Figures & data

Figure 1. XRD of synthesized product from manganese salt in the presence of plant at pH = 7 (a), at pH = 9 (b) and XRD of Mn₃O₄/CuL bio-nanocolloid (c).

Scheme 1. Synthesis of Mn₃O₄/CuL bio-nanocolloid under ultrasonic irradiation.

Figure 2. ¹H NMR (top) and ¹³C (down) spectra of L ligand.

Figure 3. FT-IR of L ligand, CuL nanocomplex, and Mn₃O₄/CuL bio-nanocolloid.

Figure 4. The EDAX (a), elemental analysis (a), SEM (b) and TEM (c) of Mn₃O₄/CuL bio-nanocolloid.

Figure 5. (a–h) Optimization of oxidation of benzyl alcohol.

Scheme 2. The oxidation of primary and secondary alcohols catalysed by Mn₃O₄/CuL bio-nanocolloid using H₂O₂ to have O₂ and water as byproducts under ultrasonic irradiation.

Figure 6. Proposed mechanism for the catalytic oxidation of benzyl alcohol by Mn₃O₄/CuL bio-nanocolloid.

Table 1. Oxidation of alcohols catalysed by Mn₃O₄/CuL bio-nanocolloid using hydrogen peroxide.

^a The reactions were run under air for 5 h at 80 °C under solvent free conditions using H₂O₂ (0.4 mmol) catalysed by Mn₃O₄/CuL bio-nanocolloid (0.007 g) using stirring.

Table 2. Comparison of the result of this study with that of related references.

Entry	Catalyst	Time (h)	Con% (Selec%)
1	Mn3O4/CuL bio-nanocolloid	5	100 (100)
2	VHPW/MCM-41/NH2	8	97 (99)
3	Im-PW/GO	7	90 (99)
4	[_-PW12O40]3−-IL-polymer support	12	99 (100)
5	Tungstate ions @periodic mesoporous organosilica-IL	12	75 (100)
6	Tetrakis(oxodiperoxotungsto) phosphate	0.7	77 (99)

(1) Tem: 80 °C; solvent: nonsolvent (this work); (2) Tem: 80 C; solvent: toluene [44]; (3) Tem: 90 C; solvent: nonsolvent [45]; (4) Tem: 80 C; solvent: CH₃CN [46]; (5) Tem: 90 C; solvent: CH₃CN/H₂O [47]; (6) Tem: 90 C; solvent: nonsolvent [48].

Figure 7. (a) The FT-IR of fresh catalyst (top) and reused catalyst after six times (down) and (b) recycling of catalyst.

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