Indium selenide/silver phosphate hollow microsphere S-scheme heterojunctions for photocatalytic hydrogen production with simultaneous degradation of tetracycline.

Designing heterojunction photocatalysts with strong interfacial interactions is an effective way to reduce the recombination of photogenerated charge carriers. Here, silver phosphate (Ag3PO4) nanoparticles are coupled with hollow flower-like indium selenide (In2Se3) microspheres by a facile Ostwald ripening and in-situ growth method, resulting in the construction of In2Se3/Ag3PO4 hollow microsphere step-scheme (S-scheme) heterojunction with a large contact interface. The flower-like In2Se3 with hollow and porous structure provides a large specific surface area and numerous active sites for photocatalytic reactions to take place. The photocatalytic activity was tested by measuring the hydrogen evolution from antibiotic wastewater, and the H2 evolution rate of In2Se3/Ag3PO4 reached 4206.4 µmol g-1h-1 under visible light, which is approximately 2.8 times greater than that of In2Se3. In addition, the amount of tetracycline (TC) degradation when it was used as a sacrificial agent is about 54.4% after 1 h. On the one hand, Se-P chemical bonds act as electron transfer channels in the S-scheme heterojunctions, which can facilitate the migration and separation of photogenerated charge carriers. On the other hand, the S-scheme heterojunctions can retain the useful holes and electrons with higher redox capacities, which is very favorable for the generation of more •OH radicals and the photocatalytic activity is greatly enhanced. This work provides an alternative design approach for photocatalysts toward hydrogen evolution in antibiotic wastewater.

Photo Energy-Enhanced Oxygen Reduction and Evolution Kinetics in Zn-Air Batteries.

Harvesting solar energy directly to boost the sluggish kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) on an air cathode is a promising approach. Herein, we synthesize a step-scheme (S-scheme) titanium dioxide-indium selenide (TiO2-In2Se3) heterojunction catalyst. The onset potential in ORR under light illumination reaches 1.28 V and the onset potential decreases to 0.48 V in OER. When an S-scheme TiO2-In2Se3 heterojunction is exposed to light, photogenerated electrons at the conduction band (CB) of TiO2 migrate to the valence band (VB) of In2Se3 due to the built-in electric field. The photogenerated electrons with strong reduction capability on the CB of In2Se3 and the holes with strong oxidation capability on the VB of TiO2 boost the cathode reaction kinetics (ORR/OER). The excellent outcome reveals tremendous commercial potential of photo-enhanced Zn-air batteries.

A dual S-scheme TiO2@In2Se3@Ag3PO4 heterojunction for efficient photocatalytic CO2 reduction.

The excellent photoresponse of semiconductors enables them to be promising photocatalysts for CO2 reduction, but practical application is hampered by fast recombination of photogenerated carriers, low CO2 capture capacity and poor stability. Herein, mesoporous hollow nanospheres of a dual S-scheme titanium dioxide@indium selenide@silver phosphate (TiO2@In2Se3@Ag3PO4) heterojunction with a large specific surface area are designed and synthesized. The products of photocatalytic CO2 reduction are CH4, CH3OH and CO with yields of 3.98, 4.32 and 8.2 µmol g-1 h-1, respectively, and the photocatalysts exhibit excellent cycle performance. The excellent photocatalytic performance is attributed to the large specific surface area of the samples and the construction of dual S-scheme heterojunctions. The large specific surface area can provide sufficient active sites for photocatalytic activity. Simultaneously, the built-in electric field (IEF) in the dual S-scheme exposed to light can facilitate the migration of photogenerated electrons from the CB of the oxidation photocatalyst (OP) to the VB of the reduction semiconductor (RP), where they recombine with the photogenerated holes on the VB of the RP, leaving behind photogenerated carriers with high redox ability for photocatalytic activity. This work provides new insights into the mechanism and design of highly efficient heterojunction photocatalysts for CO2 reduction.

Ag as Cocatalyst and Electron-Hole Medium in CeO2 QDs/Ag/Ag2Se Z-scheme Heterojunction Enhanced the Photo-Electrocatalytic Properties of the Photoelectrode.

A recyclable photoelectrode with high degradation capability for organic pollutants is crucial for environmental protection and, in this work, a novel CeO2 quantum dot (QDs)/Ag2Se Z-scheme photoelectrode boasting increased visible light absorption and fast separation and transfer of photo-induced carriers is prepared and demonstrated. A higher voltage increases the photocurrent and 95.8% of tetracycline (TC) is degraded by 10% CeO2 QDs/Ag2Se in 75 minutes. The degradation rate is superior to that achieved by photocatalysis (92.3% of TC in 90 min) or electrocatalysis (27.7% of TC in 90 min). Oxygen vacancies on the CeO2 QDs advance the separation and transfer of photogenerated carriers at the interfacial region. Free radical capture tests demonstrate that •O2-, •OH, and h+ are the principal active substances and, by also considering the bandgaps of CeO2 QDs and Ag2Se, the photocatalytic mechanism of CeO2 QDs/Ag2Se abides by the Z-scheme rather than the traditional heterojunction scheme. A small amount of metallic Ag formed in the photocatalysis process can form a high-speed charge transfer nano channel, which can greatly inhibit the photogenerated carrier recombination, improve the photocatalytic performance, and help form a steady Z-scheme photocatalysis system. This study would lay a foundation for the design of a Z-scheme solar photocatalytic system.

[Study on the mechanism of acupoint sticking therapy with Chuan fuling for treatment of asthma model rats].

OBJECTIVE: To investigate the mechanism of the acupoint sticking therapy with Chuanfuling for preventing and treating asthma. METHODS: Thirty male SD rats were randomly divided into a control group (normal saline, p.i. +no acupoint sticking+ normal saline, spray inhalation), model group (normal saline with ovalbumin, p.i. +no acupoint sticking+ normal saline with ovalbumin, spray inhalation), and acupoint sticking group (normal saline with ovalbumin, p.i. +acupoint sticking with Chuan fuling+normal saline with ovalbumin, spray inhalation), 10 rats in each group. The incubation period of nodding breath, symptom of asthmatic attack, expression level of interleukin-4 mRNA (IL-4 mRNA) and interferon-gamma mRNA (IF-gamma mRNA), as well as pathological changes on the middle leaf of right lung, were observed in each group. RESULTS: (1) Comparing with the control group, the model group was showed that the expression level of IL-4 mRNA in the peripheral blood cells (PBMC) was increased, while hyperemia, edema and eosinocyte (EOS) invasion of lung tissue was more serious (P < 0.01). (2) Comparing with the model group, the acupoint sticking group was showed that the expression level of IL-4 mRNA in PBMC was decreased, the incubation period of nodding breath was prolonged for induced asthma on the fifth and seventh time with lower frequency, while in the lung tissue EOS invasion was reduced (P < 0.05), but there were no significant changes on the hyperemia and edema (P > 0.05). CONCLUSION: Acupoint sticking for treating asthma of model rats with Chuanfuling can inhibit the expression level of IL-4 mRNA in PBMC, and the release of the inflammatory mediator and cytokine from the EOS to the air passage, in order to reduce the injury of epithelial layer and high reaction on the air passage.

[Clinical study of feiyanqing rectum condensed liquid in treating 36 cases of children syncytial viral pneumonia].

OBJECTIVE: To evaluate the clinical efficacy and mechanism of Feiyangqin Rectum Condensed Liquid (FRCL) in treating children syncytial viral pneumonia. Methods Seventy-two patients were randomly divided into two groups, the 36 patients in the treated group were treated with FRCL, and the other 36 patients in the control group simply treated with Western medicine. Efficacy of treatment on clinical condition and some immune function (IgA, IgG, CD3, CD4) were observed. RESULTS: In the treated group, 28 patients were cured (77.8%), treatment was markedly effective in 4 patients (11.1%), effective in 2 (5.5%) and ineffective in 2 (5.6%), with the total effective rate of 94.4%. The corresponding number in the control group was 20 (55.6%), 7 (19.4%), 6 (16.7%), 3 (8.3%) and 91.7%, respectively. The cure rate in the treated group was obviously superior to that in the control group (P < 0.05). FRCL could improve serum IgA, IgG, CD3, CD4, and CD4/CD8, lower serum IgE, these indexes in the treated group were significantly different to those in the control group (P < 0.05). CONCLUSION: FRCL had the action in treating children syncytial viral pneumonia without any adverse reaction, one of its mechanisms might be related to its regulation on immune function.