This work unifies the metrics of lanthanide-based LIR nanothermometers, rectifies previous misunderstanding of Sa, and provides detailed guidance.

Direct CO2 electrolysis in seawater enables the simultaneous conversion of CO2 into CO and the chlorine ions into Cl2, further meeting downstream industry needs such as phosgene synthesis and also facilitating the net consumption of CO2. As a result, the direct implementation of CO2 electrolysis in seawater is urgently required. Herein, a CoPc molecule‐implanted graphitic carbon nitride nanosheets (CoPc/g‐C3N4) electrocatalyst is prepared via a simple mechanochemistry method. The CoPc/g‐C3N4 with a negatively charged surface and preferential adsorption capability for Na+ can achieve appreciable faradaic efficiency (FE, 89.5%) toward CO with a current density of 16.0 mA cm−2 in natural seawater and also realize long‐term operation for 25 h in simulated seawater. Process monitoring further reveals that the chlorine ions in NaCl electrolyte can modulate the reaction microenvironment around the anode, which in turn has positive effects on the CO2RR in cathode. The CO2RR overall splitting in the simulated seawater exhibits a maximum FE of 98.1% towards CO at cell voltage of 3 V. This work describes the development of a carbon‐coupled CoPc molecular catalyst that can drive the CO2 electrolysis in simulated seawater and provides a promising and energy‐saving coupled reaction system for direct coproduction of CO and Cl2.

The development of luminescent probes in the biological windows has emerged as an exciting field by virtue of nanoscale spatial resolution and low tissue scattering and absorption. However, current luminescent...

Lead halide perovskites have been very promising for versatile optoelectronic applications, whereas the inherent toxicity and instability of lead halide restrict its wide application. Herein, a kind of high‐performance multifunctional phosphor is designed based on heavy concentration Er3+‐activated lead‐free double perovskite Cs2NaBiCl6 (CNBC), which realizes the self‐sensitization of Er3+ ions and emits high‐brightness pure green emission upon dual near‐infrared (dual‐NIR) excitation. The luminescence properties can be further optimized by adding sensitizers (Yb3+/Nd3+). Interestingly, the emission intensity of the green region is heightened by 212‐fold after Yb3+ ions doping, which is 40 times higher than that of the current popular phosphors (α‐NaYF4:2%Er3+,18%Yb3+). Meanwhile, the temperature sensing properties of the thermally coupled levels (Er3+:2H11/2,4S3/2) in Cs2NaBiCl6:40%Er3+ are also investigated systematically based on the luminescence intensity ratio principle, and the maximum relative sensitivity is calculated to be as high as 1.27% K‐1 (980 nm) and 1.57% K‐1 (808 nm). Fortunately, the thermal stability and the performance for temperature readout of the studied phosphors are still maintaining a high level after doping sensitizers. The insights provided by this work will broaden the scope of lead‐free halide double perovskites in the fields of luminescence and thermometry.