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ZnWO4MnPc was synthesized via a hydrothermal autoclave method with 1 wt.% manganese (iii) phthalocyanine content. The material was characterized for its structural and morphological features via X-ray diffraction (XRD) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, transmission emission microscopy (TEM), scanning electron microscopy-Energy dispersive X-ray spectroscopy (SEM-EDX), N2 adsorption–desorption at 77K, X-ray photoelectron spectroscopy (XPS), and UV-visible/diffuse reflectance spectroscopy(UV-vis/DRS). ZnWO4MnPc photocatalytic performance was tested on the degradation of bisphenol A (BPA). The ZnWO4MnPc material removed 60% of BPA after 4 h of 365 nm UV irradiation. Degradation process improved significantly to about 80% removal in the presence of added 5 mM H2O2 after 4 h irradiation. Almost 100% removal was achieved after 30 min under 450 nm visible light irradiation in the presence of same concentration of H2O2. The effect of ions and humic acid (HA) towards BPA removal was also investigated.

Food colorants processed via agro-industrial wastes are in demand as food waste management becomes vital not only for its health benefits but also for cost reduction through waste valorization. Huge efforts have been made to recover valuable components from food wastes and applied in various fields to prove their versatility rather than for feed ruminant usage only. Betalains and phenolics, antioxidant-rich compounds responsible for host color and so commonly used as natural colorants in food and cosmetic industries, are copiously present in several kinds of fruits and vegetables as well as their wastes. Technological innovation has brought extensive convenient ways of bioactive compounds extraction with many advantages like less use of solvents and energy in a short period of processing time in comparison with the classical solid–liquid extraction methods. Emerging technologies, particularly microwave irradiation, have been amenable to electromagnetic technology for decades. Practically, they have been deployed for functional and supplement food production. In this review, the feasibility of dielectric heating (microwave irradiation) in the extraction of betalain and phenolic compounds mostly from fruit and vegetable wastes was discussed.

This study investigated the synthesis of two different types of photocatalysts, namely, boron/sodium fluoride co-doped titanium dioxide (B/NaF-TiO2), and its analogue, a dye-sensitized form of silicon-based axial methoxy substituted phthalocyanine (B/NaF-TiO2SiPc). Structural and morphological characterizations were performed via X-ray diffraction (XRD); Fourier transform infra-red (FTIR); N2 adsorption–desorption at 77 K by Brunauer–Emmett–Teller (BET) and Barrett, Joyner, and Halenda (BJH) methods; transmission electron microscopy (TEM); X-ray photoelectron spectroscopy (XPS); and UV–visible absorption spectroscopy. The estimated crystallite size of pure TiO2 and pure B/NaF-TiO2 was 24 nm, and that of B/NaF-TiO2SiPc was 29 nm, whereas particle sizes determined by TEM were 25, 28, and 31 nm for pure TiO2, B/NaF-TiO2 and B/NaF-TiO2SiPc respectively. No significant differences between B/NaF-TiO2 and B/NaF-TiO2SiPc were observed for surface area by (BET) analysis (13 m2/g) or total pore volume by the BJH application model (0.05 cm3/g). Energy band gap values obtained for B/NaF-TiO2 and B/NaF-TiO2SiPc were 3.10 and 2.90 eV respectively, lower than pure TiO2 (3.17 eV). The photocatalytic activity of the synthesized materials was tested using carbamazepine (CBZ) as the model substrate. Carbamazepine removal after 4 h of irradiation was almost 100% for B/NaF-TiO2 and 70% for B/NaF-TiO2SiPc; however, the substrate mineralization proceeded slower, suggesting the presence of organic intermediates after the complete disappearance of the pollutant.

Abatement of contaminants of emerging concerns (CECs) in water sources has been widely studied employing TiO2 based heterogeneous photocatalysis. However, low quantum energy yield among other limitations of titania has led to its modification with other semiconductor materials for improved photocatalytic activity. In this work, a 0.05 wt.% CuWO4 over TiO2 was prepared as a powder composite. Each component part synthesized via the sol-gel method for TiO2, and CuWO4 by co-precipitation assisted hydrothermal method from precursor salts, underwent gentle mechanical agitation. Homogenization of the nanopowder precursors was performed by zirconia ball milling for 2 h. The final material was obtained after annealing at 500 °C for 3.5 h. Structural and morphological characterization of the synthesized material has been achieved employing X-ray diffraction (XRD), Fourier transform infra-red (FTIR) spectroscopy, Brunauer–Emmett–Teller (BET) N2 adsorption–desorption analysis, Scanning electron microscopy-coupled Energy dispersive X-ray spectroscopy (SEM-EDS), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV-Vis diffuse reflectance spectroscopy (UV-vis DRS) for optical characterization. The 0.05 wt.% CuWO4-TiO2 catalyst was investigated for its photocatalytic activity over carbamazepine (CBZ), achieving a degradation of almost 100% after 2 h irradiation. A comparison with pure TiO2 prepared under those same conditions was made. The effect of pH, chemical scavengers, H2O2 as well as contaminant ion effects (anions, cations), and humic acid (HA) was investigated, and their related influences on the photocatalyst efficiency towards CBZ degradation highlighted accordingly.