Publications

NiS₂ acts as an active and selective electrocatalyst for the two-electron O₂ reduction reaction in acids, achieving a selectivity of up to 99% and a H₂O₂ yield rate of 109 ppm h⁻¹. The catalytic mechanism is further investigated by theoretical calculations.

NaBH₄ has been considered as one of the most advantageous candidates for chemical hydrogen storage, but it is still a huge challenge to design efficient non-noble-metal catalysts for on-demand hydrogen generation from NaBH₄ hydrolysis. In this paper, we demonstrate for the first time that a spinel FeCo₂O₄ nanowire array supported on carbon cloth (FeCo₂O₄ NA/CC) behaves as an efficient earth-abundant catalyst toward NaBH₄ hydrolysis in alkaline solutions with an activation energy of 44.98 kJ mol^-1. Such FeCo₂O₄ NA/CC offers a hydrogen generation rate of 2551 ml min^-1 g^-1 under ambient conditions, with good stability and reusability. Its use as an ON/OFF switch for on-demand hydrogen generation is also demonstrated successfully.

Recent photocatalytic data for CO2 reduction by H2O using simulated sunlight have shown that, while TiO2 Evonik P25 containing Au nanoparticles (NPs; Au/P25) generates considerably higher amounts of hydrogen than methane, when P25 contains Au–Cu alloy NPs the selectivity toward methane increases dramatically. To gain insight into this photocatalytic behavior, in the present work we have performed a transient absorption spectroscopy study in the microsecond time scale of three samples, namely, Au/P25, Cu/P25, and (Au, Cu)/P25 using 355 (UV) and 532 nm (visible) lasers. The transient spectra exhibit as common features a narrower peak at about 320 nm and a broad band from 400 to 800 nm. Using oxygen as electron quencher and methanol as hole quencher, the transient signals have been assigned to charge separation. Several cases were observed, including: (i) absence of quenching attributed to the lack of accessibility of the quencher to the site, (ii) quenching of the signal, or (iii) increase of the transient signal intensity attributed to less charge recombination by removal of one of the charge carriers. Of relevance to understand the origin of the photocatalytic CO2 reduction by H2O is the quenching of the charge separated state by these two reagents. In this way, it was observed that H2O exerts a remarkable influence to the transient signal, quenching its intensity in the three samples at the two irradiation wavelengths, except for (Au, Cu)/P25 upon 532 nm excitation. Importantly, the distinctive behavior due to the presence of Cu has been attributed to the observed quenching by CO2 of the broad 400–800 nm band when excitation is performed with UV 355 nm light.

The present article reports on a simple, economical, and green preparative strategy toward water-soluble, fluorescent carbon nanoparticles (CPs) with a quantum yield of approximately 6.9% by hydrothermal process using low cost wastes of pomelo peel as a carbon source for the first time. We further explore the use of such CPs as probes for a fluorescent Hg(2+) detection application, which is based on Hg(2+)-induced fluorescence quenching of CPs. This sensing system exhibits excellent sensitivity and selectivity toward Hg(2+), and a detection limit as low as 0.23 nM is achieved. The practical use of this system for Hg(2+) determination in lake water samples is also demonstrated successfully.

Diverticular disease is a common condition that has numerous complications. Understanding the impact of diabetes mellitus (DM) on these complications, especially diverticulitis, is crucial for optimizing patient care. This study aimed to determine the relationship between type II DM and the complications of colonic diverticulitis. A retrospective cohort study was conducted on 158 patients complaining of diverticulitis at Asir Central Hospital, Abha, Saudi Arabia, between January 2013 and December 2023. Data on gender, age, and chronic diseases, especially DM, were collected. Data retrieved regarding diverticulitis included the involved segment, complications, Hinchey classification, and management. We classified the patients into groups A for nondiabetics and B for diabetics. We analyzed the data using descriptive statistics, chi-square tests, t tests, and analysis of variance. Diabetic patients were significantly older than their nondiabetic counterparts. Diabetic patients showed a significantly higher complication rate (62.5%) and a higher degree of Hinchey classification compared to nondiabetic patients (43.7%). Furthermore, in comparison to individuals without diabetes, they were hospitalized for a considerably extended period (8.06 ± 7.38 days vs 5.26 ± 5.90 days, respectively). In addition, surgical intervention was observed to be considerably more common in patients with diabetes (46.9%) than in those without diabetes (16.5%). The study showed that DM adversely affected patients with diverticulitis. A greater incidence of complications and a higher category of Hinchey classification were associated with DM compared to nondiabetics. Additionally, diabetics underwent more surgical interventions and had longer hospital stays. Diabetics with diverticulitis require particular care to prevent severe complications.