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Photocatalytic CO2 reduction coupled with water oxidation provides a fascinating approach to mitigating the issues of global warming and energy shortage. Herein, a direct Z-scheme heterojunction of Co1-C3N4@α-Fe2O3 comprising g-C3N4-supported...

Solar energy-driven direct CH4 conversion to liquid oxygenates provides a promising avenue toward green and sustainable CH4 industry, yet still confronts issues of low selectivity toward single oxygenate and use of noble-metal cocatalysts. Herein, for the first time, we report a defect-engineering strategy that rationally regulates the defective layer over TiO2 for selective aerobic photocatalytic CH4 conversion to HCHO without using noble-metal cocatalysts. (Photo)­electrochemical and in situ EPR/Raman spectroscopic measurements reveal that an optimized oxygen-vacancy-rich surface disorder layer with a thickness of 1.37 nm can simultaneously promote the separation and migration of photogenerated charge carriers and enhance the activation of O2 and CH4, respectively, to •OH and •CH3 radicals, thereby synergistically boosting HCHO production in aerobic photocatalytic CH4 conversion. As a result, a HCHO production rate up to 3.16 mmol g–1 h–1 with 81.2% selectivity is achieved, outperforming those of the reported state-of-the-art photocatalytic systems. This work sheds light on the mechanism of O2-participated photocatalytic CH4 conversion on defective metal oxides and expands the application of defect engineering in designing low-cost and efficient photocatalysts.

Helicobacter pylori is a major global pathogen and has been implicated in gastritis, peptic ulcer and gastric carcinoma. The efficacy of the extensive therapy of H. pylori infection with antibiotics is compromised by development of drug resistance and toxicity toward human gut microbiota, which urgently demands novel and selective antibacterial strategies. The present study was mainly performed to assess the in vitro and in vivo effects of a natural herbal compound, dihydrotanshinone I (DHT), against standard and clinical H. pylori strains. DHT demonstrated effective antibacterial activity against H. pylori in vitro ((MIC50/90: 0.25/0.5 μg/mL) with no development of resistance during continuous serial passaging. Time-kill curves showed strong time-dependent bactericidal activity for DHT. Also DHT eliminated preformed biofilms and killed biofilm-encased H. pylori cells more efficiently than the conventional antibiotics, metronidazole. In mouse models of multi-drug resistant H. pylori infection, dual therapy with DHT and omeprazole showed superior in vivo killing efficacy to the standard triple therapy approach. Moreover, DHT treatment induces neglectable toxicity against normal tissues and exhibits a relative safety index. These results suggest that DHT could be suitable for use as an anti-H. pylori agent in combination with proton pump inhibitor to eradicate multidrug-resistant H. pylori.