Surface Engineered Single-atom Systems for Energy Conversion.

Single-atom catalysts (SACs) are demonstrated to show exceptional reactivity and selectivity in catalytic reactions by effectively utilizing metal species, making them a favorable choice among the different active materials for energy conversion. However, SACs are still in the early stages of energy conversion, and problems like agglomeration and low energy conversion efficiency are hampering their practical applications. Substantial research focus on support modifications, which are vital for SAC reactivity and stability due to the intimate relationship between metal atoms and support. In this review, a category of supports and a variety of surface engineering strategies employed in SA systems are summarized, including surface site engineering (heteroatom doping, vacancy introducing, surface groups grafting, and coordination tunning) and surface structure engineering (size/morphology control, cocatalyst deposition, facet engineering, and crystallinity control). Also, the merits of support surface engineering in single-atom systems are systematically introduced. Highlights are the comprehensive summary and discussions on the utilization of surface-engineered SACs in diversified energy conversion applications including photocatalysis, electrocatalysis, thermocatalysis, and energy conversion devices. At the end of this review, the potential and obstacles of using surface-engineered SACs in the field of energy conversion are discussed. This review aims to guide the rational design and manipulation of SACs for target-specific applications by capitalizing on the characteristic benefits of support surface engineering.

Constructing mesoporous Zr-doped SiO2 onto efficient Z-scheme TiO2/g-C3N4 heterojunction for antibiotic degradation via adsorption-photocatalysis and mechanism insight.

Novel modified-TiO2/Zr-doped SiO2/g-C3N4 ternary composite is fabricated via an in-situ grow of porous Zr-SiO2 layer to TiO2/g-C3N4 heterojunction, which exhibits well adsorption-photocatalytic performance under simulated solar light irradiation. The nano-size mesoporous TiO2 are dispersed on the lamellar g-C3N4, and the Zr-SiO2 is in-situ fabricated onto the surface of g-C3N4 sheets. The adsorption occurs on the SiO2 layers, and doping Zr element to SiO2 enhances the adsorption of pollutants, while the photocatalytic reaction occurs on the valence band (VB) of TiO2 and conduction band (CB) of g-C3N4, which gives reactive oxygen species of ∙O2-, h+, and ∙OH for high efficient decomposition of antibiotics, i.e. berberine hydrochloride (98.11%), tetracycline (80.76%), and oxytetracycline (84.84%). The excellent adsorption capacity and Z-scheme photoinduced charge carrier migration behavior endowed the novel material with enhanced berberine hydrochloride (BH) removal in water, which approximately 2.5 and 3.8 folds than that of pure g-C3N4 and sole TiO2, respectively. Three degradation pathways are unraveled by LC-MS and theoretical calculations. Furthermore, the toxicity of intermediates was evaluated by the Toxicity Estimation Software Tool (T.E.S.T.), the result demonstrated a good application potential of M-TiO2/Zr-SiO2/g-C3N4 as an novel adsorptive photocatalyst.

Anatase quantum dots decorated silica/carbon lamellas for removal of antipsychotic drugs via adsorption-photocatalysis and toxicity evaluation.

In this work, discrete quantum dots of crystallized anatase TiO2 are successfully anchored on carbon nanosheets containing amorphous SiO2 via templated self-assembly and pyrolysis routes. The novel hybrid photocatalyst of TiO2/C/SiO2 exhibits well coupled adsorption and visible light photocatalysis on chlorpromazine (CPZ) and the rate constants are 0.0223 and 0.0198 min-1, respectively. The direct photocatalytic degradation of CPZ under static conditions reaches 91.1% within 3 h while a removal rate of 31.4% for CPZ could be retained under dynamic flow conditions, and the improved performance could be attributed to enhanced adsorption via SiO2/C and highly exposure of TiO2 QDs surface. Based on the trapping experiments, ESR, LC-MS, and toxicity evaluation, O2- free radicals are identified as main reactive species for CPZ degradation along three possible pathways, with reduced toxicities for its intermediates. The cell viability tests of photocatalytic-degraded solutions and the catalyst exhibit negligible toxicities for both intermediates and the material, suggesting the novel composite of TiO2/C/SiO2 as an environmental friendly photocatalyst for pharmaceutical wastewater treatment.

Synergistic adsorption-photocatalytic degradation of different antibiotics in seawater by a porous g-C3N4/calcined-LDH and its application in synthetic mariculture wastewater.

In this work, a modified g-C3N4/MgZnAl-calcined layered double hydroxide composite (M-CN/cLDH) was successfully fabricated via a template method. The composite material is a hierarchical porous flower-like nanostructure self-assembled from stacked hybrid flakes. The 3D M-CN/cLDH architectures exhibit a synergistic effect of adsorption and photocatalysis for eliminating typical tetracycline antibiotics in seawater, i.e., oxytetracycline (OTC), tetracycline (TC), chlortetracycline (CTC), and doxycycline (DXC). The synergistic removal rate of OTC in seawater of M-CN/cLDH is 2.73 times higher than that of g-C3N4 after 120 min of visible-light illumination, and M-CN/cLDH also performs better adsorption-photocatalytic degradation on OTC in the continuous flow reaction process. The superior adsorption capability of the M-CN/cLDH is attributed to the open porous structures of cLDH, and its excellent photocatalytic degradation activity is ascribed to the closely bonded heterojunctions between g-C3N4 (CN) and cLDH double layers. The mass spectra reveals the degradation pathways of OTC, and its byproducts are less toxic after degradation for 120 min. The exploration of the M-CN/cLDH in synthetic mariculture wastewater suggested a huge potential for its practical application. With the assistance of magnesium ammonium phosphate (MAP) precipitation pretreatment, the material can effectively retain the high OTC removal rate in the synthetic mariculture wastewater circumstance.

Adsorption-photocatalysis synergistic removal of contaminants under antibiotic and Cr(VI) coexistence environment using non-metal g-C3N4 based nanomaterial obtained by supramolecular self-assembly method.

Due to the rapid development of modern industry, the coexistence of antibiotics and inorganic heavy metals pollutants in wastewater has become a universal phenomenon. Therefore, developing efficient and eco-friendly photocatalyst for mixed pollutants degradation is significant. In this work, a well-designed phosphorus and sulfur co-doped g-C3N4 with feeble N vacancies catalyst (P/S-g-C3Nx) was fabricated by supramolecular self-assembly method, and was applied to remove berberine hydrochloride (BH) and Cr(VI) simultaneously with the synergy of adsorption-photocatalysis. A series of experiments was conducted to unveil the synergistic mechanism. The kinetic models indicated that the adsorption of P/S-g-C3Nx improved the BH removal process by accelerating the photo-degradation, because the adsorption rate > surface degradation rate > bulk degradation rate. Besides, the photo-degradation process improved the BH removal rate by regenerating the adsorption sites of P/S-g-C3Nx. Moreover, from the experiments in BH-Cr(VI) mixed solution system, the existence of BH also enhanced the surface adsorption of Cr(VI) in P/S-g-C3Nx sample, and the reduction rate of Cr(VI) was also promoted with the existence of BH. Overall, the results of this investigation suggest that the adsorption-photocatalysis synergy method is an efficient way to eliminate organic pollutant and Cr(VI) simultaneously.

Traumatic cardiac injury following sternal fracture: a case report and literature review.

Myocardial injury used to be thought as one of the major complications associated with sternal fracture even though recent studies on injuries associated with fracture of sternum are contrary to this belief. Many authors now believe the presence of sternal fracture is no longer indicative of occult injuries to the underlying structure such as the heart. However, clinicians should still maintain a high index of suspicion for the presence cardiac tamponade in cases presented as blunt chest trauma as early diagnosis and surgical intervention is vital to the patient's survival. Presented is a case of a 38-year-old female patient transferred to our hospital after being injured in a motor vehicle accident. On arrival her blood pressure (BP) was 90/50 mmHg but it then dropped to 60/30 mmHg two hours later. Although her chest roentgenography and electrocardiography (ECG) did not reveal any significant findings, the two-dimensional echocardiography was performed and revealed a moderate amount of pericardial effusion. The chest computerized tomography (CT) scan later revealed sternal fracture and cardiac tamponade. A diagnosis of cardiac rupture resulting from sternal fracture following blunt chest trauma was made. Under midline sternotomy, her right atrial rupture was repaired. The patient was reported to be doing well during a three months, post-operative follow-up.