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Molybdenum disulfide (MoS2), a promising two‐dimensional photothermal material, possesses the capability to convert solar irradiation into thermal energy. This conversion is beneficial for processes like wastewater treatment and seawater desalination. Nevertheless, the influence of the surface chemical properties of MoS2, particularly its wettability, on the evaporation rate of water confined to the surface remains unexplored. In our study, we demonstrate that the wettability degree of MoS2 significantly influences its water evaporation rate performance. Interestingly, this parameter can be simply and accurately modulated by altering the synthesis time of MoS2. We synthesized MoS2 via a simple hydrothermal method at three different durations: 16, 20, and 24 h, at 200°C. Subsequently, we impregnated the resultant MoS2 onto air‐laid paper (ALP), forming a solar‐driven evaporator system. We found that the MoS2 nanosheets synthesized within the shortest duration (MoS2‐16 h) exhibited the highest evaporation rate of 1.77 kg m−2 h−1, along with 92% energy efficiency. MoS2‐16 h resulted in MoS2 rich in defects, featuring the largest surface area and the smallest contact angle. The hydrophilic areas of MoS2‐16 h facilitated the continuous diffusion of water molecules through defect sites, treating them as contact lines. Additionally, the expansive surface area introduced a larger region for light absorption, enhancing water‐solid interactions. The presence of molybdenum oxide on the surface of the nanosheet system also contributed to superior wettability behavior. Notably, all the tested MoS2/ALP systems in this study displayed excellent performance in salt rejection and heavy metal ion concentration reduction. [ABSTRACT FROM AUTHOR]

The modification of ternary metal oxide to improve the photoelectrocatalysis (PEC) properties of TiO2 photocatalyst is a hot issue in environmental and resource applications. Herein, we present a novel photoelectrocatalytst of Se doped-TiO2/Ti nanotube arrays (Se@TiO2/Ti-NTAs) for high-efficiency degradation of diazinon pesticide. The Se@TiO2/Ti-NTAs were prepared to treat the TiO2-NTAs in Se-TiO2 sol-gel for 10 min, which was followed by calcination in air at 200 °C for 1 h. Optical absorption spectroscopy of the Se@TiO2/Ti-NTAs indicated that there is a red-shift in the optical energy gap to 2.95 eV if compared to the pristine TiO2/Ti NTAs, which suggests that the new photoelectrocatalyst is photoactive under visible light irradiation. We evaluated the photoactivity of the sample by using it as the photoelectrocatalyst in the degradation of diazinon pesticides under the PEC process. The results showed that the Se@TiO2/Ti-NTAs can degrade 95.62% for 1 h under visible light irradiation, which is equivalent to the degradation rate constant of 0.0183 s−1. For comparison, the pristine TiO2/Ti NTAs only degrades the diazinon as high as 87.65%, even then under UV light irradiation. Our result also indicated that the Se@TiO2/Ti-NTAs promote active photoelectron transfer and active radical formation, such as •OH and •O2−, for rapid diazinon pesticide degradation. The Se@TiO2/Ti-NTAs photoelectrode should be a potential platform for environmental pollution treatment. [ABSTRACT FROM AUTHOR]

The effect of Te doping of the TiO2/Ti nanotube arrays (NTAs) on the photoelectrochemical chemical oxygen demand (COD) detection has been investigated. It is found that the Te doping has enhanced the photoelectrocatalytic properties of the TiO2/Ti NTAs electrode. This indicated by the linearity, accuracy, and repeatability of measurement of the test compounds chemicals. The Te-TiO2/Ti NTAs shows an excellent linearity to all test compounds up to 10 μM of concentration. It is only up to 5 μM in pristine TiO2/Ti NTAs system. In term of accuracy, the Te-TiO2/Ti NTAs electrode can provide the measurement accuracy of up to 100% fit to the theoretical value for all test compound chemical. It is only less than 80% for TiO2/Ti NTAs electrode. Meanwhile, the repeatability of measurement for the electrode, the Te-TiO2/Ti NTAs exhibits 1.8% RSD value, which is lower than the pristine TiO2/Ti NTAs, i.e., 2%. The enhancement of the photoelectrocatalytic properties of the TiO2 by Te doping is due to the lowering of electron and hole recombination during the photoactivation, promoting massive surface reaction with organic compounds and improving the sensing sensitivity. The Te-TiO2/Ti NTAs should find the extensive application of PECOD detection of organic contamination in the environment. [ABSTRACT FROM AUTHOR]

The concern over increasing environmental contamination by dye agents from textile industries, such as Reactive yellow 105, requires a special catalyst that can rapidly and effectively eradicate the dye chemical. Here, we demonstrate a new design of catalyst, i.e., Te doped TiO2/Ti composite electrode, that promotes highly active charge transfer with the Reactive yellow 105 dye for efficient photoelectrocatalytic degradation under visible light irradiations. Our results show that the new photocatalyst effectively degrades up to 90% of 0.5 ppm of the Reactive yellow 105 dye under visible light irradiation within 60 min, which is equivalent to the degradation rate constant of 0.0611 M-1 min-1. It is impressively higher than the pristine photocatalyst (TiO2/Ti) of which it only degrades 70 and 65% of dye compound under UV and Vis irradiation respectively or equivalent to degradation kinetic rate as low as 0.037 and 0.0361 M−1 min−1, respectively. The degradation of dye compound is enhanced to 100% when the new catalyst is applied in photoelectrocatalytic degradation process under visible light irradiation or approximately 95% degradation under UV light irradiation. The Te doped TiO2/Ti photoelectrocatalyst can be a new platform for rapid Reactive yellow 105 dye contamination in the environment. Te doping enhances visible photoactivity of TiO2 nanotube on Ti electrode. [ABSTRACT FROM AUTHOR]

Photoelectrochemical oxidation processes offer a highly sensitive method to detect organic pollutants from wastewaters. Photoactive semiconducting material is the key factor in this process that accelerates the oxidation of the organic pollutant agent for sensitive detection. Chalcogenide-doped TiO2 system has so far come up as a potential photocatalyst system for photoelectrochemical detection of organic compounds. Here, we report a highly sensitive detection of chemical oxygen demand of organic compound pollutant using sulfurized-TiO2 (S-TiO2/Ti) nanotube array (NTA) photoelectrocatalyst. S-TiO2/Ti NTA that is prepared via consecutive anodization of Ti sheet and TiO2 sulfurization process exhibited a high sensitivity to COD value of organic compound pollutants, such as Red HE-3B (Reactive Red 120), Red HE-7B (Reactive Red 141), and Blue HE-RD (Reactive Blue 160). Our results indicated that the COD value is linearly correlated with the concentration of the organic compounds and is close to the COD theoretical value, inferring the high accuracy of the detection. This explains that the new S-TiO2/Ti NTA photoelectrocatalyst effectively enhances the electron transfer dynamic during the electrochemical measurement of an organic pollutant, which is reflected by an impressive proportionality of electrochemical current to the concentration of the pollutant sample. The S-TiO2/Ti NTA promises a highly efficient pollutant detection in the environment. [ABSTRACT FROM AUTHOR]