In aim to increase the yield of conventional solar still, Portland cement has been used in two forms: sprayed powder and adhesive layer in order to study firstly their thermal behavior on the output, secondly to see the effect of the heat storage medium amount on the yield and thirdly to see the photocatalyst behavior of the cement on the quality of distillate; the experiments carried out in Ouargla University revealed that: For the same amount, powder cement is more beneficial in quantity term but in term of quality and according to distilled water analysis, the cement layer is better. This improvement in quantity and quality of distillate is due from side to the heat storage medium and to the other side to photocatalyst behavior of Portland cement. Best result is obtained by spraying 150 g i.e. 0.906 (kg of powder cement/m(2) of absorber area) which led to an improvement of the output by of 51.14%. (C) 2016 Elsevier B.V. All rights reserved.