Supercapacitors are energy storage devices with high power density, rapid charge/discharge rate, and excellent cycle stability. Carbon-based supercapacitors are increasingly attracting attention because of their large surface area and high porosity. Carbon-based materials research has been recently centered on biomass-based materials due to the rising need to maintain a sustainable environment. Cellulose and lignin constitute the major components of lignocellulose biomass. Since they are renewable, sustainable, and readily accessible, lignin and cellulose-based supercapacitors are economically viable and environmentally friendly. This review aims to systematically analyze published research findings on electrospun lignin, cellulose, and lignin/cellulose nanofibers for use as supercapacitor electrode materials. A rigorous scientific approach was employed to screen the eligibility of relevant articles to be included in this study. The research questions and the inclusion criteria were clearly defined. The included articles were used to draw up the research framework and develop coherent taxonomy of literature. Taxonomy of research literature generated from the included articles was classified into review papers, electrospun lignin, cellulose, and lignin/cellulose nanofibers for use as supercapacitor electrode materials. Furthermore, challenges, recommendations, and research directions for future studies were equally discussed extensively. Before this study, no review on electrospun lignin/cellulose nanofiber-based supercapacitors has been reported. Thus, this systematic review will provide a reference for other researchers interested in developing biomass-based supercapacitors as an alternative to conventional supercapacitors based on petroleum products.

In this work, thin films of copper oxide (CuO) have been prepared using spraypyrols is technique. The energy gap was determined for samples of the copper oxide (CuO) at different temperatures ranging from (150 to 330) 0 C. The absorption and transmission spectra, shows the energy gap for (CuO) in the range from (2.44-2.19) eV. These values are comparable to the actual values.

The wide spread of phenols and their toxicity in the environment pose a severe threat to the existence and sustainability of living organisms. Rapid detection of these pollutants in wastewaters has attracted the attention of researchers from various fields of environmental science and engineering. Discoveries regarding materials and method developments are deemed necessary for the effective detection and remediation of wastewater. Although various advanced materials such as organic and inorganic materials have been developed, secondary pollution due to material leaching has become a major concern. Therefore, a natural-based material is preferable. Clay is one of the potential natural-based sorbents for the detection and remediation of phenols. It has a high porosity and polarity, good mechanical strength, moisture resistance, chemical and thermal stability, and cation exchange capacity, which will benefit the detection and adsorptive removal of phenols. Several attempts have been made to improve the capabilities of natural clay as sorbent. This manuscript will discuss the potential of clays as sorbents for the remediation of phenols. The activation, modification, and application of clays have been discussed. The achievements, challenges, and concluding remarks were provided.

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