Graphite-like graphitic carbon nitride (g-C 3 N 4 ) has gained considerable interest in the past few years. However, merely a few studies have been undertaken regarding the application of g-C 3 N 4 for metal adsorption and visible-lightdriven reduction of aromatic nitro compounds. Here, we describe a versatile method for the preparation of g-C 3 N 4 nanocomposite decorated with magnetite nanoparticles (g-C 3 N 4 @Fe 3 O 4 NPs) that subsequently showed their efficiency in sequestration of Cr(VI)/Cr(III) and NaBH 4 -mediated conversion of 2-nitroaniline (2-NA) and 4-nitroaniline (4-NA) under visible-light exposure. The as-synthesized g-C 3 N 4 @Fe 3 O 4 NPs adsorbent revealed excellent water dispersibility, superior magnetic property, and porous structure. Numerous surface hydroxyls (−OH) and amino groups (−N, −NH, −NH 2 ) enabled g-C 3 N 4 @Fe 3 O 4 NPs to rapidly isolate Cr(VI) from aqueous solution through applying an outer magnetic field. The adsorbed Cr(VI) on the g-C 3 N 4 @Fe 3 O 4 NPs surface offered a maximum equilibrium adsorption capacity of 555 mg g −1 , and their absorption behavior followed the Langmuir isotherm and pseudo-second-order kinetics model. The morphology, surface properties, crystalline structure, and chemical compositions of g-C 3 N 4 @Fe 3 O 4 NPs were thoroughly investigated. In real-world applications, g-C 3 N 4 @Fe 3 O 4 NPs was implemented for the determination of total chromium in industrial soil sludge samples. Additionally, NaBH 4 -induced reduction of 2-NA to 2-aminoaniline and 4-NA to 4-aminoaniline catalyzed by g-C 3 N 4 @ Fe 3 O 4 NPs (catalyst loading as low as 20 mg) was achieved within 8 min.

Electronic structure, electrical transport, dc and ac magnetization properties of the hole substituted (Sr 2+ ) partially B-site disordered double perovskite Pr 2-x Sr x CoMnO 6 system have been investigated.Electronic structure was probed by employing X-ray photoemission spectroscopy (XPS) measurements. The study suggested the presence of mixed valence states of the B-site ions (Co 2+ /Co 3+ and Mn 3+ /Mn 4+ ) with significant enhancement of the average oxidation states due to hole doping. The mere absence of electronic states near the Fermi level in the valence band (VB) spectra for both of the pure (x=0.0) and Sr doped (x=0.5) systems indicated the insulating nature of the samples. Sr substitution is observed to increase the spectral weight near the Fermi level suggesting for an enhanced conductivity of the hole doped system. The temperature variation of electrical resistivity measurements revealed the insulating nature for both the systems, thus supporting the VB spectra results. The resistivity curves were observed to follow the variable range hopping (VRH) mechanism in the entire temperature range while the analysis showed a significance enhancement in the carrier concentration due to the hole doping. The dc magnetization data divulged a Griffiths like phase above the long range ordering temperature. A typical re-entrant spin glass like phase driven by the inherent anti-site disorder (ASD) has been maidenly recognized by ac susceptibility study for both the pure and doped systems. Most interestingly, the emergence of a new cluster glass like phase (immediately below the magnetic ordering temperature and above the spin-glass transition temperature) solely driven by the Sr substitution has been unravelled by ac magnetization dynamics study. Observation of these dual glassy states in a single system is scarce and hence placed the present system amongst the rare materials. The isothermal magnetization measurements further probed the exhibition of the giant exchange bias effect emanated from the existence of multiple magnetic phases.

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Exchange bias and enhanced coercivity in phase separated La0.45Sr0.55MnO3 and Pr0.55(Ca0.65S0.35)