Nickel hydroxide (Ni(OH)₂) is a valuable compound derived from nickel, widely utilized across various fields because of its versatile properties. This study aimed to characterize as-prepared β-Ni(OH)₂ via chemical precipitation using various analytical techniques. X-ray diffraction (XRD) analysis confirmed the formation of a β-Ni(OH)₂ hexagonal crystalline structure, validating the successful precipitation. Fourier-transform infrared spectroscopy (FTIR) spectra exhibited main characteristic peaks of (υOH) and υ(NiO), corresponding to the formation of nickel hydroxide (Ni(OH)₂). Subsequently, X-ray photoelectron spectroscopy (XPS) revealed a prominent peak for Ni²⁺ oxidation, confirming the successful precipitation of nickel hydroxide at pH 6.5, which identifies the existence of impurities, such as chlorine and calcium, from the waste matrix. Scanning electron microscopy (SEM) micrographs demonstrated stratified granules with a nearly pure brucite crystalline phase, typical of β-Ni(OH)₂. Furthermore, the surface morphology revealed a coarse texture and uneven clustering, suggesting possible elevated oxide levels on the Ni surface. Energy-dispersive X-ray spectroscopy (EDX) confirmed the presence of nickel (Ni) and oxygen (O), with Ca impurities attributed to the chemical precipitation process. Particle size distribution analysis estimated an average particle size of 2.0 µm. Additionally, the precipitation of nickel was investigated using inductively coupled plasma optical emission spectroscopy (ICP-OES). Ni was observed in decreasing order, 62.7 g/L, 0.8 g/L, and 0.501 g/L in the pregnant leach, precursor solution, and solid precipitate (cake), respectively. The separation of Ni(OH)₂ through the precipitation process from the waste (acidic chloride media) enabled efficient recycling and re-use of nickel, which provides a cost-effective and environmentally friendly method for the highly efficient utilization of waste (acidic chloride media).

Monitoring river systems is crucial for understanding and managing water resources, predicting natural disasters, and maintaining ecological balance. Assessment of heavy metal pollution derived valuable data which are critical for the environmental management and regulatory compliance of the Jukskei River. Heavy elements were evaluated in the Jukskei River for seasonal impact, potential health risks, and contamination level with concentration levels ranging from 6900 mg/kg iron (Fe) to 0.85 mg/kg cadmium (Cd) in the dry sampling season and 6900 mg/kg Fe to 0.26 mg/kg Cd in the wet season. Enrichment factor analysis indicated high contamination levels of Fe and Pb in both dry and wet seasons. Moreover, pollution indicators revealed extremely high contamination of geo-accumulation and enrichment factors in the downstream to upstream in both seasons with a mild contamination factor for mercury (Hg). Principal Component Analysis revealed anthropogenic sources of arsenic (As), Cd, and Pb due to wastewater and agricultural pesticide application while Thorium (Th), uranium (U) and Hg were attributed as a results of gold mining activities. ANOVA and Pearson correlation analysis showed a high and moderate link between As–Pb, Cd–Pd, and As–Hg, which are significantly correlated. The potential ecological risk index assessment revealed a significant impact of heavy metals on the freshwater ecosystem.

In this study, Titanium dioxide (TiO₂) nano-powder was prepared using a sol-gel process with and without surfactant. A typical non-ionic surfactant (Triton X-100) was used during the process. The phase compositions of TiO₂ and surfactant-assisted TiO₂ (TiO₂-sa) were investigated by FTIR, X-ray diffraction (XRD), scanning electron microscope-energy dispersive spectroscopy (SEM-EDS), and thermogravimetric analysis (TGA). Brunauer–Emmett–Teller (BET) was used to determine the nano-powder’s specific surface area and pore size distribution. Moreover, transmission electron microscopy (TEM) and selected area electron diffraction (SAED) analysis exhibited particle size in the range of 65–85 nm and polycrystalline phase, respectively. UV-vis spectrophotometer showed high absorption as dominating the visible region (438–450 nm) with relative redshift and reduced bandgap from 2.98 to 3.12 eV upon adding surfactant on TiO₂. X-ray fluorescence spectroscopy (XRF) exhibits high purity TiO₂ with more than 82% composition with the lowest relative standard deviation (RSD %). Moreover, the photoluminescence (PL) of TiO₂-sa showed enhanced oxygen vacancies and surface defects which reduce the direct electron-photon (e/h+) pair recombination. TiO₂-sa illustrated promising characteristic features of an active photocatalyst for the degradation of organic pollutants.

The increasing population has subjected rivers and streams to high levels of both industrial and domestic pollution. Significant environmental challenges have been brought about by their effects, particularly with regard to biota, ecosystem processes, soil quality, and groundwater pollution. This study examined the effects of human activity by applying pollution index models to evaluate the input of toxic elements in river sediments. Prior to sediment quality analysis, the total amount of arsenic (As), lead (Pb), cadmium (Cd), mercury (Hg), thorium (Th), and uranium (U) was determined in the concentration range of 1.09–10.0 mg/kg, 8.53–475 mg/kg, 0.12–0.16 mg/kg, 4.85–77.5 mg/kg, 3.14–5.9 mg/kg and 0.93–2.86 mg/kg, respectively. The enrichment factor, contamination factor, pollution load index, and geo-accumulation index revealed alarmingly high levels of Pb and Hg contamination at some sampling points, which are related to possible human input, ranging from severe enrichment to considerable contamination. The low ranges of pollution indices of some toxic elements suggest enrichment through the natural weathering process and atmospheric deposition. The Pearson correlation coefficient revealed a significant correlation between Pb-Fe and As-Fe, suggesting the possibility of acid mine contamination. Continual monitoring of river sediment is essential to minimize the impact of toxic elements to sustain sediment health and quality.

An alternative electrosynthesis of PdTe, using the electrochemical atomic layer deposition (E-ALD) method, is reported. The cyclic voltammetry technique was used to analyze Au substrate in copper (Cu²⁺), and a tellurous (Te⁴⁺) solution was used to identify UPDs and set the E-ALD cycle program. Results obtained using atomic force microscopy (AFM) and scanning electron microscopy (SEM) techniques reveal the nanometer-sized flat morphology of the systems, indicating the epitaxial characteristics of Pd and PdTe nanofilms. The effect of the Pd:Te ratio on the crystalline structure, electronic properties, and magnetic properties was investigated using a combination of density functional theory (DFT) and X-ray diffraction techniques. Te-containing electrocatalysts showed improved peak current response and negative onset potential toward ethanol oxidation (5 mA; −0.49 V) than Pd (2.0 mA; −0.3 V). Moreover, DFT ab initio calculation results obtained when the effect of Te content on oxygen adsorption was studied revealed that the d-band center shifted relative to the Fermi level: −1.83 eV, −1.98 eV, and −2.14 eV for Pd, Pd₃Te, and Pd₃Te₂, respectively. The results signify the weakening of the CO-like species and the improvement in the PdTe catalytic activity. Thus, the electronic and geometric effects are the descriptors of Pd₃Te₂ activity. The results suggest that Pd₂Te₂ is a potential candidate electrocatalyst that can be used for the fabrication of ethanol fuel cells.

The global issue of water quality degradation that exacerbates water scarcity prompted establishment of strategic water management systems. The majority of anthropogenic activities that affect water quality are indispensable and economical. Despite its importance for achieving economic expansion, prosperity, and advancement on a national and international scale, industrialization is a primary cause of adverse environmental effects. There is significant strain on rivers and dams from chemical spills, fertilizers and pesticides, personal hygiene products, wastewater discharge, and land drainage due to lack of proper water treatment infrastructures or wilful activities of illegal disposal. The developing era of scientific research is focused on effective technologies for water-pollution monitoring. This study is interested in exploration of environmental forensics using forensic-analytical techniques such as aerial photography, satellite analytics, and chemometric and spectroscopic techniques to identify sources of water pollutants. This approach is of great importance in connecting the identified pollutants to their emission sources in order to provide efficient long-term strategies for a holistic water management system. The environmental forensics approach in this study can improve comprehension of pollution that will assist national departments and policy makers in charge of pollution control in the geographical locations to ensure that water polluters abide by applicable laws.