Utilizing stress release effect for achieving high-performance photoelectrochemical hydrogen evolution on CQDs-enriched SnSe nanosheets

[Display omitted] •This demonstrates a novel stress release strategy for the development of high-performance photoelectrochemical hydrogen evolution.•Choosing semiconductor materials (SnSe) with higher light absorption coefficients as the main photocatalysts.•The photocatalytic activity of SnSe is greatly enhanced by size thinning and the introduction of CQDs, resulting in a twofold increase compared to commercial P25.•By size thinning and the introduction of CQDs, the SnSe material also achieves a significant enhancement in its photoelectrocatalytic activity, with a carrier density of 2.38 × 1031 cm−3. The effective development of solar hydrogen production technology is one of the most efficient ways to avoid secondary environmental pollution. However, the photocatalytic hydrogen production efficiency of traditional semiconductor materials is too low, which is far from being able to alleviate the energy crisis and address related environmental issues. Here, we introduced SnSe, known for its high absorption coefficient in solar cell technology, as the main catalyst, and proposed a novel stress release effect strategy to overcome the bottleneck in photocatalytic hydrogen production. As a result, we have successfully released the interlayer stress of SnSe and introduced uniformly distributed carbon quantum dots (CQDs) on its surface. The experimental tests demonstrate that the release of interlayer stress and the introduction of CQDs not only enhance the photocatalytic hydrogen evolution activity, achieving twice the performance of commercial P25, but also significantly improve the separation efficiency of photo-generated electron-hole pairs, with a carrier density reaching 2.38 × 1031 cm−3. Compared to unmodified SnSe, the modified SnSe exhibits significantly enhanced photoelectrocatalytic performance, with a hydrogen evolution efficiency reaching 6.99 mmol∙h−1∙cm−2. This study demonstrates a novel stress release strategy for developing high-performance photoelectrochemical hydrogen evolution.