The present study reports the photo-Fenton degradation of phenolic compounds (phenol, 2-chloro-4-nitrophenol and 4-chloro-2-nitrophenol) in aqueous solution using mesoporous Cu/Al(2)O(3)-MCM-41 nanocomposite as a heterogeneous photo-Fenton-like catalyst. The in situ incorporation of mesoporous Al(2)O(3) (MA) into the framework of MCM-41 (sol-gel method) forms Al(2)O(3)-MCM-41 and wetness impregnation of Cu(II) on Al(2)O(3)-MCM-41 generates mesoporous Cu/Al(2)O(3)-MCM-41 composite. The effects of pH and H(2)O(2) concentration on degradation of phenol, 2-chloro-4-nitrophenol and 4-chloro-2-nitrophenol are studied. Kinetics analysis shows that the photocatalytic degradation reaction follows a first-order rate equation. Mesoporous 5 Cu/Al(2)O(3)-MCM-41 is found to be an efficient photo-Fenton-like catalyst for the degradation of phenolic compounds. It shows nearly 100% degradation in 45 min at pH 4. The combined effect of small particle size, stabilization of Cu(2+) on the support Al(2)O(3)-MCM-41, ease reducibility of Cu(2+) and visible light activeness are the key factors for quick degradation of phenolic compounds by Cu/Al(2)O(3)-MCM-41.

In recent years, metal/metal oxide functionalized mesoporous materials have received increasing attention in science and technology due to their fascinating properties, such as a large surface area, mesoscopic bulky shape, and interconnected porous structures enabling them to be one of the most promising materials for catalysis and photo catalysis. This review summarizes the recent developments in design, preparation and applications of transition metal/metal oxide promoted MCM-41 for production of hydrogen energy and removal of aqueous pollutants. After a brief introduction of these materials and synthetic strategies, their characterizations and applications in aqueous pollutant degradation by photocatalysis/photo-Fenton processes and H 2 energy production by photocatalytic water splitting are summarized. Finally, the future perspectives directions for this promising field are also discussed. under the guidance of Dr K. M.

h i g h l i g h t sMesoporous ZrO 2 -MCM-41synthesized by in situ incorporation process. CuO@ZM-41 synthesized by modification of CuO onto the ZrO 2 -MCM-41. CuO@ZM-41nacomposite shows semiconductor behavior and mesoporosity. High surface area, lower e À and h + recombination are enhancing the photo-reduction. g r a p h i c a l a b s t r a c tMesoporous nanocomposite (CuO@ZM-41) is synthesized by incorporating mesoporous ZrO 2 (Z) into MCM-41 (M-41) framework followed by loading of CuO by wetness impregnation method. The synergism between CuO and the support material mesoporous ZM-41 and efficient light absorption on the surface of the composite is the key factor for the reduction Cr 6+ to Cr 3+ within 30 min time. a b s t r a c tMesoporous nanocomposites of CuO/ZrO 2 -MCM-41 (CuO@ZM-41) was designed by incorporating mesoporous ZrO 2 (Z) into the high surface area MCM-41 (M-41) framework followed by loading CuO by wetness impregnation method keeping Si/Zr ratio 10. The nanocomposites were studied under PXRD, N 2 sorption, DRS spectra, FTIR, XPS, NMR, HRTEM and PL to evaluate structural, morphological, optical properties and also the mesoporosity nature of the samples. The photo-reduction of Cr 6+ was performed over CuO@ZM-41 by varying pH, substrate concentration, and irradiation time and catalyst dose. Among all the catalysts, 2 CuO@ZM-41 was found to be efficient photocatalyst for the photo-reduction of Cr 6+ . Nearly 100% reduction of Cr 6+ has been achieved by 2 CuO@ZM-41 within 30 min. Intra-particle mesoporosity, high surface area, presence of CuO nanorods and electron transfer properties are the key factors for enhancing the photo-reduction activity of 2CuO@ZM-41.

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A series of promising visible light driven ZnFe 2 O 4 modified Al 2 O 3 À MCM-41 nanocomposites were designed by wet impregnation method by loading different wt % (2, 6, 10) of ZnFe 2 O 4 on the surface of mesoporous Al 2 O 3 À MCM-41. All the prepared photocatalysts were analyzed by using X-ray diffractometers (XRD), Scanning electron microscope (SEM), N 2 sorption, Ultra violet-Visible Diffuse reflectance spectroscopy (UV-Vis DRS), Xray photoelectron spectroscopy (XPS), Fourier-transmission infrared spectroscopy (FTIR) and High-resolution transmission electron microscope (HRTEM) techniques to uncover and confirm the formation of phase, morphology and porous structure of the prepared nanocomposites. In the photo-Fenton reaction, the ZnFe 2 O 4 modified Al 2 O 3 À MCM-41 nanocomposites exhibit a significant catalytic activity for the photo-Fenton degradation of phenol (40 min, 99%) via photocatalysis and photocatalytic reduction of Cr (VI) (60 min, 66%) under sunlight with an excellent reusability nature. The high photo-Fenton activity of the composites is mainly attributed to mesoporosity and high surface area of support Al 2 O 3 À MCM-41, proper light harvestation and increased charge transfer efficiency by active species ZnFe 2 O 4 , and suitable band edge potential for hydroxyl radical generation. The photo-Fenton activities were further supported by the high photocurrent (0.29 mA/cm 2 ) generated by the nanocomposite ZnFe 2 O 4 modified Al 2 O 3 À MCM-41. These results open up a new route for ZnFe 2 O 4 modified Al 2 O 3 À MCM-41as an efficient photo-Fenton catalyst for environmental remediation with superior activity and higher stability.

Mesoporous Cu/Al(2)O(3)-MCM-41 composite was synthesized by two step processes; in situ incorporation of high surface area mesoporous Al(2)O(3) (MA) into the framework of MCM-41 (in situ method) followed by impregnation of Cu(II) by incipient wetness method. The interesting thing is that starch was used for the first time as template for the preparation of high surface area MA. To evaluate the structural and electronic properties, these catalysts were characterized by low angle X-ray diffraction (LXRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), UV-vis DRS, FTIR and photoluminescent (PL) spectra. The various cationic dye such as methylene blue (MB), methyl violet (MV), malachite green (MG) and rhodamine 6G (Rd 6G) of high concentration 500 mg L(-1) were degraded and adsorbed very efficiently (100%) using the 5 Cu/Al(2)O(3)-MCM-41 composite within 30 and 60 min, respectively. The high and quick removal of such concerted cationic organic dyes and also mixed dyes (MB+MV+MG+Rd 6G) by means of photocatalysis/adsorption is basically due to the combined effect three characteristics of synthesized mesoporous 5 Cu/Al(2)O(3)-MCM-41 composite. These characteristics are intra-particle mesoporosity, electron transfer and ˙OH radical generation under solar light.

The synergistic effect of metallic Cu, CuO and g-C3N4 over the widespread surface of MCM-41 plays the vital role for effective H2 evolution.

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